application-a1-office-action-response-draft.docx

1014-00005 · Optiwave Semiconductor Corp · Prosecution Files/Sub-Family A

application-a1-office-action-response-draft.docx DOCUMENT IP / Technology

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DRAFT — PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT v0.3 — INCOMPLETE — Last edited August 28, 2023 Prepared by: Christy Bauer (USPTO Reg. No. 74,329), Lead Associate, intellectual Property Group, Calderwood & Harkness LLP C&H Matter No.: 1014-00005

STATUS: DRAFT NOT YET REVIEWED BY RESPONSIBLE PARTNER (C. Bloom). Work suspended due to client budget freeze effective August 11, 2023. DO NOT FILE.

DEADLINE NOTE: The Office Action response deadline was originally three (3) months from the Office Action mailing date. A two-month Extension of Time was filed by Peter Vassiliev on September 6, 2023 (fee of $640.00, small entity rate). The absolute six-month statutory deadline for response under 37 C.F.R. § 1.136(a) is March 9, 2025. No further extensions of time are available under 37 C.F.R. § 1.136(a). Failure to file a response by March 9, 2025 will result in abandonment of U.S. Application No. 17/672,204.

RESPONSE TO NON-FINAL OFFICE ACTION

IN THE UNITED STATES PATENT AND TRADEMARK OFFICE

RESPONSE TO NON-FINAL OFFICE ACTION

Commissioner for Patents United States Patent and Trademark Office P.O. Box 1450 Alexandria, VA 22313-1450

Dear Commissioner:

Applicant Optiwave Semiconductor Corp. ("Applicant" or "OWS"), by and through its undersigned attorneys of record at Calderwood & Harkness LLP, hereby respectfully submits this Response to the Non-Final Office Action in the above-identified application. Applicant requests entry of the amendments and consideration of the remarks set forth herein.

I. PRELIMINARY REMARKS

Applicant respectfully submits this Response to the Non-Final Office Action mailed in the above-identified application (the "Office Action"). The mailing date of the Office Action is to be confirmed from the prosecution file maintained by the United States Patent and Trademark Office ("USPTO").

Applicant Optiwave Semiconductor Corp. respectfully requests that the Examiner consider the amendments to the claims and the supporting remarks set forth below, and that all pending rejections be reconsidered and withdrawn in view thereof.

A two-month Extension of Time was filed with the USPTO on September 6, 2023, accompanied by the requisite fee of $640.00 (small entity rate), by Peter Vassiliev of Calderwood & Harkness LLP. Accordingly, this Response is timely filed within the extended period for response.

This application, U.S. Application No. 17/672,204, was filed on January 9, 2023, and claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/297,841, filed January 10, 2022. The provisional application expired on January 10, 2023, and priority thereto has been preserved through the timely filing of the present non-provisional application on January 9, 2023, one day prior to the expiration of the twelve-month period for claiming priority under 35 U.S.C. § 119(e).

Calderwood & Harkness LLP is the attorney of record for Applicant in this matter. All correspondence should be directed to:

Calderwood & Harkness LLP

Attn: Intellectual Property Group

555 California Street, 42nd Floor San Francisco, CA 94104

This Response has been prepared by Christy Bauer (USPTO Reg. No. 74,329), Lead Associate, intellectual Property Group, Calderwood & Harkness LLP. Catherine Bloom (USPTO Reg. No. 58,412), Partner, serves as the responsible partner for this prosecution matter.

II. STATUS OF THE CLAIMS PRIOR TO AMENDMENT

The claims of U.S. Application No. 17/672,204 were originally filed on January 9, 2023, as part of the non-provisional application. As filed, the application contained a total of twenty-four (24) claims, numbered Claims 1 through 24, comprising three (3) independent claims and twenty-one (21) dependent claims.

The independent claims are directed to the following subject matter:

Claim 1 is directed to a multi-channel silicon-photonic Mach-Zehnder modulator apparatus comprising a segmented traveling-wave electrode architecture. Claim 1 recites the structural elements of the modulator, including the photonic waveguide structure, the Mach-Zehnder interferometer arms, and the segmented traveling-wave electrode configuration. Claims 2 through 11 depend from Claim 1 and recite additional structural and functional features of the apparatus.

Claim 12 is directed to a method of modulating optical signals using the multi-channel silicon-photonic Mach-Zehnder modulator. Claim 12 recites steps for receiving an input optical signal, splitting the signal into a plurality of channels, applying modulation via the segmented traveling-wave electrode architecture, and combining the modulated signals for output. Claims 13 through 17 depend from Claim 12 and recite additional method steps and parameters.

Claim 18 is directed to an integrated photonic circuit system for data-center optical interconnects incorporating the multi-channel silicon-photonic Mach-Zehnder modulator with segmented traveling-wave electrode architecture. Claim 18 recites the system-level context in which the modulator operates, including the optical transceiver module, the photonic integrated circuit substrate, and the electronic driver circuitry. Claims 19 through 24 depend from Claim 18 and recite additional system-level features and specifications.

No amendments to the claims have been entered prior to this Response. The claims as originally filed are the claims that were examined in the Office Action.

The Office Action rejected certain of the claims under 35 U.S.C. § 102 (anticipation) and 35 U.S.C. § 103 (obviousness), citing as primary references two United States patents owned by Pinnacle Optics, Inc.: U.S. Patent No. 10,823,417, issued November 3, 2020 (hereinafter, the "'417 patent"); and U.S. Patent No. 11,105,662, issued August 31, 2021 (hereinafter, the "'662 patent"). The specific rejections are summarized in Section III below.

III. SUMMARY OF THE OFFICE ACTION REJECTIONS

The Office Action sets forth rejections of certain claims under 35 U.S.C. §§ 102 and 103. Applicant summarizes these rejections below for the convenience of the Examiner and to provide context for the amendments and arguments presented in Sections IV and V of this Response.

A. Rejections Under 35 U.S.C. § 102(a)(1) — Anticipation

The Office Action rejected Claims 1, 2, 3, 5, 7, 12, 13, 18, and 19 under 35 U.S.C. § 102(a)(1) as being anticipated by U.S. Patent No. 10,823,417 (the '417 patent), assigned to Pinnacle Optics, Inc., and issued November 3, 2020.

The Examiner took the position that the '417 patent discloses a silicon-photonic Mach-Zehnder modulator incorporating a segmented traveling-wave electrode structure, and that each element of the rejected claims is expressly disclosed in the '417 patent. Specifically, the Examiner provided a claim-element mapping in which the '417 patent's description of a multi-segment electrode array for velocity-matched modulation in a silicon photonic platform was mapped to the claimed "segmented traveling-wave electrode architecture." The Examiner further mapped the '417 patent's disclosure of a multi-channel waveguide arrangement to the claimed "multi-channel" modulator configuration, and the '417 patent's Mach-Zehnder interferometric modulation scheme to the claimed Mach-Zehnder modulator structure.

The Examiner's claim chart identified specific columns and lines of the '417 patent as corresponding to each element of the rejected claims. Applicant addresses the specifics of this mapping in Section V.B below.

B. Rejections Under 35 U.S.C. § 103 — Obviousness

The Office Action rejected Claims 4, 6, 8, 9, 10, 11, 14, 15, 16, 17, 20, 21, 22, 23, and 24 under 35 U.S.C. § 103 as being unpatentable over U.S. Patent No. 10,823,417 (the '417 patent) in view of U.S. Patent No. 11,105,662 (the '662 patent), also assigned to Pinnacle Optics, Inc., and issued August 31, 2021.

The Examiner reasoned that it would have been obvious to a person of ordinary skill in the art at the time of the invention to combine the teachings of the '417 patent with those of the '662 patent. The '662 patent is directed to electrode fabrication processes for silicon-photonic modulators, including methods of forming segmented electrode structures on silicon-on-insulator (SOI) substrates. The Examiner asserted that a person of ordinary skill in the art would have been motivated to combine the '417 patent's modulator architecture with the '662 patent's fabrication techniques and additional electrode design parameters to arrive at the subject matter of the dependent claims, with a reasonable expectation of success.

The Examiner also cited additional secondary references in connection with certain dependent claims, including references directed to traveling-wave electrode design for high-speed electro-optic modulators, impedance matching in RF electrode structures, and silicon photonic integration techniques for data-center applications. Applicant will address each of these additional references in Section V.D below.

C. Any Other Rejections or Objections

[Draft note — CB: Review the Office Action for any claim objections (e.g., informalities, antecedent basis issues), specification objections, or drawing objections. If any such objections were raised, they should be summarized here and addressed in the amendments and/or remarks below. PENDING — to be completed upon full review of the Office Action.]

To the extent the Office Action raised any objections to the claims, specification, or drawings on the basis of informalities or other non-substantive grounds, Applicant addresses those matters below and makes any necessary corrections in the amendments set forth herein.

IV. AMENDMENTS TO THE CLAIMS

Applicant hereby amends the claims as set forth below. Additions to the claim language are indicated by underlining; deletions are indicated by strikethrough. The claims not listed below remain as previously presented.

A. Amended Independent Claim 1

Claim 1 (Currently Amended):

A multi-channel silicon-photonic Mach-Zehnder modulator apparatus, comprising:

(a) a silicon-on-insulator substrate having a plurality of optical waveguide channels formed thereon;

(b) a Mach-Zehnder interferometer structure for each of the plurality of optical waveguide channels, each Mach-Zehnder interferometer structure comprising a first arm and a second arm configured to receive and recombine portions of an input optical signal;

(c) a segmented traveling-wave electrode architecture disposed along at least one arm of each Mach-Zehnder interferometer structure, the segmented traveling-wave electrode architecture comprising a plurality of electrode segments electrically coupled in series along a propagation direction of the traveling-wave electrode, and

(d) a radio-frequency signal input configured to apply a modulating electrical signal to the segmented traveling-wave electrode architecture for modulating the optical signal propagating through each Mach-Zehnder interferometer structure.

The key amendment to Claim 1 is the addition of the tapered impedance-matching region as a structural limitation of each electrode segment within the segmented traveling-wave electrode architecture. This amendment specifies that the electrode segments are not uniform at their interfaces but instead incorporate a tapered impedance-matching region that provides a graduated impedance transition between adjacent segments. The taper geometry is defined by a monotonic variation in at least one physical dimension — electrode width, electrode gap spacing, or electrode thickness — along the tapered impedance-matching region. This feature is a specific, structural design-around element that distinguishes the claimed invention from the uniform, non-tapered segment interfaces disclosed in the Pinnacle Optics '417 patent.

As noted herein, this design-around feature was the principal point of distinction identified in the Calderwood & Harkness LLP freedom-to-operate analysis delivered to Optiwave Semiconductor Corp. on October 14, 2022, and forms the basis of OWS's differentiated modulator product architecture.

B. Amended Independent Claim 12

Claim 12 (Currently Amended):

A method of modulating optical signals using a multi-channel silicon-photonic Mach-Zehnder modulator, the method comprising:

(a) receiving an input optical signal at a silicon-on-insulator photonic integrated circuit comprising a plurality of optical waveguide channels;

(b) splitting the input optical signal into a plurality of channel signals, each channel signal directed along a respective Mach-Zehnder interferometer structure comprising a first arm and a second arm;

(c) applying a modulating electrical signal to a segmented traveling-wave electrode architecture disposed along at least one arm of each Mach-Zehnder interferometer structure, the segmented traveling-wave electrode architecture comprising a plurality of electrode segments electrically coupled in series along a propagation direction,

(d) modulating each of the plurality of channel signals by electro-optic interaction between the modulating electrical signal and the optical signal in at least one arm of the Mach-Zehnder interferometer structure; and

(e) recombining the modulated channel signals to produce a modulated output optical signal.

The amendment to Claim 12 introduces a corresponding method step specifying that the modulating electrical signal propagates through the tapered impedance-matching region between adjacent electrode segments, with the graduated impedance transition defined by the same structural parameters recited in amended Claim 1. The amendment maintains parallel structure with Claim 1 and ensures that the method claim captures the functional operation of the tapered impedance-matching feature.

C. Amended Independent Claim 18

Claim 18 (Currently Amended):

An integrated photonic circuit system for data-center optical interconnects, the system comprising:

(a) an optical transceiver module configured for operation at data rates of at least 800 Gbps per module;

(b) a photonic integrated circuit disposed within the optical transceiver module, the photonic integrated circuit comprising a silicon-on-insulator substrate;

(c) a multi-channel silicon-photonic Mach-Zehnder modulator formed on the photonic integrated circuit, the Mach-Zehnder modulator comprising:

(i) a plurality of optical waveguide channels;

(ii) a Mach-Zehnder interferometer structure for each of the plurality of optical waveguide channels; and

(iii) a segmented traveling-wave electrode architecture disposed along at least one arm of each Mach-Zehnder interferometer structure, the segmented traveling-wave electrode architecture comprising a plurality of electrode segments electrically coupled in series,

(d) electronic driver circuitry electrically coupled to the segmented traveling-wave electrode architecture and configured to generate modulating electrical signals at a symbol rate supporting per-channel data rates of at least 100 Gbps per channel; and

(e) an output optical interface configured to couple the modulated optical signals from the photonic integrated circuit to an optical fiber for data-center interconnect transmission .

The amendment to Claim 18 incorporates the tapered impedance-matching feature at the system level, consistent with the amendments to Claims 1 and 12. In addition, Claim 18 has been amended to further specify the data-center interconnect context, including express recitation of compatibility with 800G and 1.6T optical transceiver standards, reflecting the intended commercial application of OWS's modulator technology.

D. Amendments to Dependent Claims

Applicant has reviewed the dependent claims (Claims 2–11, 13–17, and 19–24) and does not believe that conforming amendments to the existing dependent claims are required at this time, as the dependent claims incorporate the limitations of the independent claims by reference and will automatically reflect the amendments to Claims 1, 12, and 18.

[Draft note — CB: Consider adding 2–3 new dependent claims narrowing the taper geometry with specific parameters. Potential new claims could recite:

• A specific impedance gradient range (e.g., an impedance transition of between 5 Ω and 15 Ω over a taper length of between 50 μm and 200 μm);

• A specific taper angle or taper profile (e.g., a linear taper profile or an exponential taper profile);

• Specific materials for the tapered region (e.g., doped silicon, aluminum, copper, or gold electrode materials with specified resistivity ranges).

Need to discuss with Dr. Lena Strickland regarding preferred embodiment parameters and the specific taper geometries that have been fabricated and tested in OWS's production devices. PENDING.]

Applicant reserves the right to propose additional dependent claims directed to specific tapered impedance-matching parameters in a subsequent filing or supplemental response, if appropriate.

V. REMARKS IN SUPPORT OF PATENTABILITY

A. Overview of Amendments and Argument Strategy

The amendments set forth in Section IV above add the tapered impedance-matching feature as a structural limitation to each of the three independent claims (Claims 1, 12, and 18). This feature — specifying that each electrode segment comprises a tapered impedance-matching region configured to provide a graduated impedance transition between adjacent segments — is a critical structural distinction that differentiates the claimed invention from the prior art cited in the Office Action.

The tapered impedance-matching feature is fully supported by the specification as filed on January 9, 2023. Specifically, the as-filed specification describes the tapered impedance-matching region in detail at paragraphs [0047]–[0055], with reference to Figures 5A, 5B, 6, and 7. Figure 5A depicts a schematic plan view of the segmented traveling-wave electrode architecture showing the tapered impedance-matching regions at the interfaces between adjacent electrode segments. Figure 5B provides a magnified view of a single tapered impedance-matching region, illustrating the monotonic variation in electrode width along the taper. Figure 6 presents a graph of the impedance profile along the length of the segmented electrode, showing the graduated impedance transitions at each taper. Figure 7 depicts an alternative embodiment in which the impedance transition is effectuated by variation in electrode gap spacing rather than electrode width.

No new matter has been introduced by the amendments. All claim limitations added by the amendments find express support in the specification as originally filed, in full compliance with 35 U.S.C. § 132 and 37 C.F.R. § 1.121. Applicant submits that the amendments are proper under the patent rules and that no new matter rejection is warranted.

Applicant respectfully submits that the amendments to Claims 1, 12, and 18, as described above, overcome all outstanding rejections under 35 U.S.C. §§ 102 and 103. The detailed arguments in support of this position are set forth in Sections V.B and V.C below.

B. Traversal of § 102 Rejection — Anticipation by the '417 Patent

Applicant respectfully traverses the rejection of Claims 1, 2, 3, 5, 7, 12, 13, 18, and 19 under 35 U.S.C. § 102(a)(1) as anticipated by U.S. Patent No. 10,823,417 (the '417 patent, Pinnacle Optics, Inc.).

To anticipate a claim under § 102, a single prior art reference must disclose each and every element of the claimed invention, arranged as in the claim, either expressly or inherently. Verdegaal Bros., Inc. v. Union Oil Co. of Cal., 814 F.2d 628, 631 (Fed. Cir. 1987). The Federal Circuit has consistently held that "[t]he identical invention must be shown in as complete detail as is contained in the ... claim." Richardson v. Suzuki Motor Co., 868 F.2d 1226, 1236 (Fed. Cir. 1989). There is no room under the anticipation standard for combining elements from different embodiments or for supplying missing elements through inference; the reference must teach each element either explicitly or inherently. Atofina v. Great Lakes Chem. Corp., 441 F.3d 991, 999 (Fed. Cir. 2006).

The '417 patent does not disclose the newly claimed tapered impedance-matching region. Applicant provides the following detailed element-by-element analysis, which is based in part on the claim chart prepared by Christy Bauer in October 2022 comparing the OWS pending claims against the Pinnacle '417 patent (referenced in the C&H freedom-to-operate analysis delivered October 14, 2022).

Element-by-Element Comparison:

The '417 patent discloses a silicon-photonic Mach-Zehnder modulator with a segmented traveling-wave electrode structure. This much is not disputed. However, the critical distinction lies in the nature of the electrode segment interfaces. The '417 patent describes an electrode architecture in which adjacent electrode segments are connected at uniform, non-tapered interfaces. The '417 patent repeatedly emphasizes that each electrode segment has a substantially constant characteristic impedance along its length, and that the interfaces between adjacent segments are designed to maintain impedance uniformity across the entire electrode array.

Specifically, the '417 patent states:

"Each electrode segment is designed to have a substantially uniform cross-sectional profile along its length, providing a consistent characteristic impedance of approximately 50 Ω throughout the segmented electrode array." ('417 patent, col. 8, ll. 32–37.)

"The interfaces between adjacent electrode segments are configured to minimize discontinuities in the electrode cross-section, thereby maintaining impedance uniformity and reducing signal reflections at segment boundaries." ('417 patent, col. 9, ll. 5–10.)

These passages confirm that the '417 patent's electrode segmentation geometry is predicated on uniform impedance at the segment interfaces — the opposite of the tapered, graduated impedance transition claimed by OWS. There is no disclosure, suggestion, or teaching anywhere in the '417 patent of a tapered impedance-matching region at the segment interfaces. The '417 patent does not describe any monotonic variation in electrode width, electrode gap spacing, or electrode thickness at or near the segment interfaces.

Applicant has reviewed all embodiments, figures, and descriptions in the '417 patent. None of the disclosed embodiments includes a tapered impedance-matching region. The '417 patent's Figures 3, 4A, and 4B depict the electrode segments with abrupt, rectangular transitions at the segment boundaries. The '417 patent's specification does not use the terms "taper," "tapered," "impedance-matching region," "graduated impedance," "impedance transition," or any equivalent terminology.

Because the tapered impedance-matching region is a distinct structural element that is entirely absent from any embodiment of the '417 patent, the '417 patent cannot anticipate the amended claims. The § 102(a)(1) anticipation rejection should therefore be withdrawn with respect to all claims.

Conclusion: The amended claims recite a tapered impedance-matching region that is not disclosed, taught, or suggested by the '417 patent. Each of the independent claims as amended includes this element as a structural limitation. Because the '417 patent fails to disclose each and every element of the amended claims, the rejection under 35 U.S.C. § 102(a)(1) is overcome. Applicant respectfully requests that the Examiner withdraw this rejection.

C. Traversal of § 103 Rejection — Obviousness over the '417 Patent in View of the '662 Patent

Applicant respectfully traverses the rejection of Claims 4, 6, 8, 9, 10, 11, 14, 15, 16, 17, 20, 21, 22, 23, and 24 under 35 U.S.C. § 103 as being unpatentable over U.S. Patent No. 10,823,417 (the '417 patent) in view of U.S. Patent No. 11,105,662 (the '662 patent), both assigned to Pinnacle Optics, Inc.

A claim is unpatentable under § 103 only if the differences between the claimed subject matter and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art. 35 U.S.C. § 103. The Supreme Court has established that the obviousness inquiry requires consideration of (1) the scope and content of the prior art, (2) the differences between the prior art and the claimed invention, (3) the level of ordinary skill in the pertinent art, and (4) any objective indicia of non-obviousness. Graham v. John Deere Co., 383 U.S. 1, 17–18 (1966). Furthermore, there must be "some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007) (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)).

The '662 Patent Does Not Disclose or Suggest the Tapered Impedance-Matching Region.

The '662 patent is directed to electrode fabrication processes for silicon-photonic modulators, including methods of forming segmented electrode structures on silicon-on-insulator (SOI) substrates. While the '662 patent addresses various aspects of electrode fabrication — including metal deposition techniques, lithographic patterning of electrode segments, and post-fabrication impedance tuning — it does not disclose or suggest a tapered impedance-matching region between adjacent electrode segments.

The '662 patent's fabrication methods are directed to producing electrode segments with uniform cross-sectional profiles, consistent with the design philosophy articulated in the '417 patent. The '662 patent does not describe any process step for forming a taper or graduated transition region at the electrode segment interfaces. There is no suggestion in the '662 patent that impedance matching between adjacent segments should be achieved through a tapered geometry rather than through uniform electrode design.

Accordingly, even when considered in combination, the '417 patent and the '662 patent do not teach or suggest the tapered impedance-matching region recited in the amended claims.

Lack of Motivation to Combine.

Even assuming arguendo that the individual references could somehow be read to collectively disclose the claimed elements (which Applicant does not concede), the Examiner has not articulated a proper motivation to combine the references in a manner that would arrive at the claimed tapered impedance-matching feature. Neither the '417 patent nor the '662 patent suggests that the uniform segment interfaces should be replaced with a tapered impedance-matching region. To the contrary, both references are consistent in their emphasis on maintaining impedance uniformity across the electrode array. There is no suggestion in either reference that impedance non-uniformity at the segment interfaces would be desirable, and no disclosure of a tapered geometry as a means of achieving impedance matching.

The Examiner's motivation to combine the references appears to be based on the general proposition that a person of ordinary skill would look to the '662 patent's fabrication techniques to manufacture the modulator of the '417 patent. However, this reasoning does not account for the specific tapered impedance-matching feature, which is not taught by either reference individually or in combination. The mere fact that two references share a common technological field does not establish a motivation to combine them in a manner that produces the specific claimed invention. In re Rouffet, 149 F.3d 1350, 1357–58 (Fed. Cir. 1998).

Teaching Away.

The '417 patent affirmatively teaches away from the tapered impedance-matching approach recited in the amended claims. As discussed in Section V.B above, the '417 patent repeatedly emphasizes uniform segment impedance as a design goal. The '417 patent expressly states that "the interfaces between adjacent electrode segments are configured to minimize discontinuities in the electrode cross-section, thereby maintaining impedance uniformity" ('417 patent, col. 9, ll. 5–10). This design philosophy is fundamentally inconsistent with the claimed tapered impedance-matching region, which intentionally introduces a spatially varying impedance profile at each segment interface.

A reference that "teaches away" from the claimed invention — i.e., that "criticize[s], discredit[s], or otherwise discourage[s]" the claimed approach — weighs against a finding of obviousness. In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004). The '417 patent's emphasis on impedance uniformity constitutes a teaching away from the non-uniform, tapered impedance approach of the present invention. A person of ordinary skill in the art, reading the '417 patent, would have been led in the opposite direction from the claimed invention — toward uniform segment interfaces rather than toward graduated impedance transitions.

Secondary Considerations of Non-Obviousness.

Applicant further submits that objective indicia of non-obviousness support the patentability of the amended claims. The Supreme Court has recognized that secondary considerations — including commercial success, long-felt but unresolved need, and failure of others — are relevant to the obviousness inquiry and "may often be the most probative and cogent evidence" of non-obviousness. Graham v. John Deere Co., 383 U.S. at 17–18.

Commercial Success. OWS has achieved commercial success with products incorporating the tapered impedance-matching feature claimed in the present application. OWS's design-around modulator architecture, which employs the tapered impedance-matching electrode geometry, has been incorporated into OWS's 800G optical transceiver product line and has generated substantial commercial revenue.

[Draft note — CB: Need to gather supporting evidence from Dr. Lena Strickland and Dr. Feng-Yi Chen on commercial performance data. Also need to verify FY 2022/2023 product revenue attributable to the design-around architecture. OWS FY 2022 revenue was $68.1M; FY 2023 revenue was $47.3M (down due to sector downturn, not product issue). Need to establish a nexus between the commercial success and the specific tapered impedance-matching feature. Consider requesting a declaration from Dr. Strickland or Sandra Koh (OWS IP Manager) in support. PENDING.]

Long-Felt But Unresolved Need. There exists a long-felt but unresolved need in the silicon photonics industry for improved signal integrity at high data rates (800G and 1.6T) in silicon-photonic modulators. The transition from 400G to 800G and 1.6T data rates has exposed significant signal integrity challenges at electrode segment boundaries in conventional segmented traveling-wave electrode designs. The tapered impedance-matching feature of the present invention directly addresses this need by reducing signal reflections and improving the quality of the modulating RF signal along the electrode.

[Draft note — CB: Need to identify and cite industry publications documenting this long-felt need. Consider citing IEEE/OSA publications on signal integrity challenges in high-speed silicon photonic modulators. Also consider citing OFC (Optical Fiber Communication Conference) proceedings from 2020–2022 discussing electrode design challenges at 800G data rates. PENDING.]

Conclusion: The combination of the '417 patent and the '662 patent does not render the amended claims obvious. Neither reference discloses or suggests the tapered impedance-matching region. There is no motivation to combine the references to arrive at the claimed feature. The '417 patent teaches away from the claimed approach. And secondary considerations — including commercial success and long-felt but unresolved need — support a finding of non-obviousness. Applicant respectfully requests that the Examiner withdraw the § 103 rejection.

D. Distinction of Additional Secondary References

[Draft note — CB: This section is incomplete. Need to review all secondary references cited by the Examiner in the Office Action and draft individualized arguments distinguishing each reference from the amended claims. Each secondary reference should be analyzed for whether it discloses or suggests the tapered impedance-matching feature, and arguments should be provided as to why the secondary references, individually or in combination with the primary references, do not render the amended claims obvious. PENDING PARTNER REVIEW AND CLIENT INPUT.]

Applicant will provide additional arguments addressing each secondary reference cited by the Examiner in the Office Action. To the extent any secondary reference is asserted to disclose an impedance-matching feature, Applicant will demonstrate that such disclosure, if any, is materially different from the specific tapered impedance-matching region recited in the amended claims.

E. Support in the Specification for Amended Claims

Applicant confirms that all limitations added by the amendments to Claims 1, 12, and 18 are fully supported by the specification as originally filed on January 9, 2023, in U.S. Application No. 17/672,204.

The tapered impedance-matching feature is described in detail in the following sections of the as-filed specification:

• Paragraphs [0047]–[0049]: General description of the tapered impedance-matching region and its function in providing a graduated impedance transition between adjacent electrode segments, including the design rationale for reducing RF signal reflections and improving modulation bandwidth.

• Paragraph [0050]: Description of the monotonic variation in electrode width as one mechanism for achieving the impedance taper, including specific dimensional ranges for the taper length (50 μm to 200 μm) and the impedance transition (from approximately 45 Ω to 55 Ω over the taper length in the preferred embodiment).

• Paragraphs [0051]–[0052]: Alternative embodiments in which the impedance transition is effectuated by variation in electrode gap spacing or electrode thickness, or by a combination of geometric parameters.

• Paragraphs [0053]–[0055]: Simulation results and experimental data demonstrating the performance advantages of the tapered impedance-matching region, including reduced return loss (S11) and improved electro-optic bandwidth compared to conventional uniform segment interfaces.

• Figure 5A: Schematic plan view of the segmented traveling-wave electrode architecture showing the tapered impedance-matching regions at each segment interface.

• Figure 5B: Magnified view of a single tapered impedance-matching region, showing the monotonic variation in electrode width along the taper.

• Figure 6: Graph of the impedance profile along the length of the segmented electrode, illustrating the graduated impedance transitions at each taper.

• Figure 7: Alternative embodiment with impedance transition effectuated by variation in electrode gap spacing.

Applicant confirms that the amended claims comply with the written description and enablement requirements of 35 U.S.C. § 112(a). The specification provides a clear, complete description of the tapered impedance-matching feature that demonstrates that the inventors were in possession of the claimed invention at the time of filing. The specification further enables a person of ordinary skill in the art to make and use the claimed invention without undue experimentation.

[Draft note — CB: Need to cross-check the specification paragraphs referenced above against the U.S. Provisional Application No. 63/297,841, filed January 10, 2022, by Kessler & Morin LLP (the provisional was drafted by Dr. Helen Kessler at K&M). The purpose of this cross-check is to confirm that the tapered impedance-matching limitation has priority support in the provisional application, such that the effective filing date for the amended claims is January 10, 2022 (the provisional filing date) rather than January 9, 2023 (the non-provisional filing date). If the tapered impedance-matching feature is not described in the provisional, the effective filing date for the amended claims may be the non-provisional filing date of January 9, 2023, which could affect the prior art landscape. PENDING.]

VI. CONCLUSION

In view of the foregoing amendments and remarks, Applicant respectfully submits that all pending claims as amended are in condition for allowance. Applicant requests that the Examiner reconsider and withdraw all rejections set forth in the Non-Final Office Action, including the rejections under 35 U.S.C. §§ 102 and 103.

If the Examiner believes that any issue remains unresolved after consideration of this Response, Applicant respectfully requests an interview with the Examiner to discuss the claims and the prior art. Catherine Bloom (Reg. No. 58,412) and Christy Bauer (Reg. No. 74,329) are available for an interview at the Examiner's convenience, and can be reached at the telephone number set forth below.

Applicant believes that all claims as amended are patentable over the cited prior art and respectfully requests favorable action on this application.

VII. SIGNATURE BLOCK

[DRAFT — Signature placeholder. Not yet executed. This Response is to be signed by Catherine Bloom (Reg. No. 58,412), responsible partner, upon completion of partner review. DO NOT FILE without partner signature.]

Respectfully submitted,

CALDERWOOD & HARKNESS LLP

By: ________

Catherine Bloom (Reg. No. 58,412) Partner, intellectual Property Group

Christy Bauer (Reg. No. 74,329) Lead Associate, intellectual Property Group

555 California Street, 42nd Floor San Francisco, CA 94104 Telephone: [To be confirmed]

Email: [To be confirmed]

Date: ________

VIII. CERTIFICATE OF SERVICE / CERTIFICATE OF MAILING

CERTIFICATE OF ELECTRONIC FILING

I hereby certify that this Response to Non-Final Office Action, together with all accompanying papers and amendments, is being filed electronically via the USPTO Patent Center electronic filing system on the date indicated below, in accordance with 37 C.F.R. § 1.6(a)(4).

By: ________

Name: ________

Registration No.: ________

Date: ________

[Draft note: Certificate of electronic filing has not yet been populated. To be completed upon finalization of the Response and authorization to file. Filing will be accomplished via Patent Center (formerly EFS-Web). Confirm filing receipt number and timestamp upon submission.]

APPENDIX: INCOMPLETE WORK / OPEN ITEMS LOG

PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT — NOT FOR FILING This Appendix is an internal tracking document of Calderwood & Harkness LLP and is subject to the attorney-client privilege and the attorney work product doctrine. This Appendix is not part of the Response to be filed with the USPTO. It is maintained for internal case management purposes only and must not be transmitted to the client, filed with the USPTO, or disclosed to any third party without prior authorization from Catherine Bloom.

C&H Matter No.: 1014-00005 Application No.: 17/672,204 Status as of: August 28, 2023

Open Items:

1. Partner Review by Catherine Bloom — NOT YET CONDUCTED. Draft v0.3 of this Response has not been reviewed by the responsible partner, Catherine Bloom (Reg. No. 58,412). Partner review is required before this Response may be finalized or filed. Work on this matter was suspended effective August 11, 2023, due to the client budget freeze (see Item 9 below).

2. Client Review by Sandra Koh (OWS IP Manager) — NOT YET SENT. The draft Response has not been transmitted to the client for review. Sandra Koh, IP Manager at Optiwave Semiconductor Corp., is the designated client contact for prosecution matters. Client review and approval are required before filing. The draft should not be sent to the client until partner review is completed.

3. Technical Verification with Dr. Lena Strickland and Dr. Feng-Yi Chen Regarding Taper Geometry Parameters — PENDING. The specific taper geometry parameters (e.g., taper length, impedance gradient, taper profile) recited in the amended claims should be verified against the preferred embodiment parameters used in OWS's production devices. Dr. Strickland (lead inventor) and Dr. Chen (co-inventor and fabrication lead) are the appropriate technical contacts. This verification is necessary before finalizing the claim amendments and before considering whether to propose new dependent claims directed to specific taper parameters.

4. Cross-Check of Priority Support in Provisional Application No. 63/297,841 (Originally Drafted by Kessler & Morin LLP) — PENDING. The tapered impedance-matching limitation added by the amendments must be cross-checked against the disclosure of the provisional application to confirm that priority support exists. The provisional was drafted by Dr. Helen Kessler at Kessler & Morin LLP ("K&M") and filed January 10, 2022. If the tapered impedance-matching feature is not described in the provisional, the effective filing date for the amended claims would be the non-provisional filing date of January 9, 2023, which could affect the prior art analysis. C&H should obtain a copy of the provisional specification from K&M or from the prosecution file and conduct a detailed comparison.

5. Secondary Considerations Evidence Gathering (Commercial Success Data) — PENDING. Evidence of commercial success of OWS's design-around products incorporating the tapered impedance-matching feature is needed to support the secondary considerations argument in Section V.C. Relevant data includes: (a) FY 2022 and FY 2023 revenue attributable to products incorporating the design-around architecture; (b) customer adoption data for OWS's 800G transceiver modules; (c) any industry recognition or awards for the design-around technology. Note: OWS FY 2022 total revenue was $68.1M; FY 2023 total revenue was $47.3M (the decline is attributable to the broader semiconductor sector downturn and is not indicative of product performance issues). Revenue attributable specifically to the design-around architecture has not yet been disaggregated. A declaration from Dr. Strickland or Sandra Koh may be necessary to establish the nexus between commercial success and the claimed features.

6. Individualized Arguments for Each Examiner-Cited Secondary Reference — NOT DRAFTED. Section V.D of the Response (Distinction of Additional Secondary References) is incomplete. Each secondary reference cited by the Examiner must be reviewed and distinguished individually. This task cannot be completed until the full Office Action has been reviewed and all cited references have been obtained and analyzed.

7. Decision on Whether to File RCE If Amendments Are Deemed to Change Scope. If the Examiner determines that the amendments to the independent claims change the scope of the claims such that a Request for Continued Examination (RCE) is required, the estimated cost is $2,000 in USPTO fees at the small entity rate, in addition to approximately 40–55 attorney hours for preparing the RCE and any supplemental response. At the blended discounted rates applicable to the OWS engagement, this represents approximately $22,000–$30,000 in total professional fees, exclusive of USPTO fees. This expenditure would require separate budget authorization from the client, which is currently subject to the budget freeze (see Item 9).

8. Confirm Whether New Dependent Claims Should Be Added — Requires Discussion with Prosecution Strategy Team. As noted in Section IV.D, consideration should be given to adding 2–3 new dependent claims narrowing the taper geometry with specific parameters. This decision should be made in consultation with the prosecution strategy team (Catherine Bloom, Christy Bauer, and Peter Vassiliev) and with input from the inventors (Dr. Strickland and Dr. Chen).

9. Budget Authorization — All Work Suspended as of August 11, 2023. All work on this matter has been suspended effective August 11, 2023, pursuant to the Project Lighthouse budget freeze imposed by Harborview Partners (OWS's majority equity investor). The quarterly IP spend has been capped at $25,000 per quarter, compared to a pre-freeze average of approximately $87,400 per quarter. The current matter (C&H Matter No. 1014-00005) has an outstanding balance of fees and costs that must be reconciled against the quarterly cap. No further work should be performed on this matter without express written authorization from Sandra Koh (OWS) or direction from Catherine Bloom, following confirmation that budget has been allocated.

10. Absolute Deadline — March 9, 2025. The absolute deadline to file this Response is March 9, 2025. No further extensions of time are available under 37 C.F.R. § 1.136(a). A two-month extension of time was purchased on September 6, 2023, at a cost of $640.00 (small entity rate). If the Response is not filed by March 9, 2025, U.S. Application No. 17/672,204 will be ABANDONED. Abandonment would result in the irrevocable loss of the foundational U.S. patent application for OWS's core modulator architecture and the tapered impedance-matching design-around claim scope. Per the C&H freedom-to-operate analysis delivered October 14, 2022, loss of this application would leave OWS at "moderate-to-high" infringement risk vis-à-vis Pinnacle Optics' '417 patent (U.S. Patent No. 10,823,417) with no defensive patent position. This risk assessment should be communicated to OWS's management and to Veltrano Capital Partners as part of any budget negotiation.

END OF APPENDIX — PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT

Application No.:	17/672,204
Filing Date:	January 9, 2023
Title of Invention:	Multi-Channel Silicon-Photonic Mach-Zehnder Modulator with Segmented Traveling-Wave Electrode Architecture
Named Inventors:	Dr. Rajan Menon, Dr. Lena Strickland, Dr. Feng-Yi Chen, Dr. Arjun Dasgupta
Applicant/Assignee:	Optiwave Semiconductor Corp.
Confirmation No.:	[To be confirmed]
Art Unit:	[To be confirmed]
Examiner:	[To be confirmed]
Attorney Docket No.:	OWS-2022-A1
Customer No.:	[C&H customer number — to be confirmed]
Priority Claim:	Claims benefit of U.S. Provisional Application No. 63/297,841, filed January 10, 2022

DRAFT — PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT v0.3 — INCOMPLETE — Last edited August 28, 2023 Prepared by: Christy Bauer (USPTO Reg. No. 74,329), Lead Associate, intellectual Property Group, Calderwood & Harkness LLP C&H Matter No.: 1014-00005
STATUS: DRAFT NOT YET REVIEWED BY RESPONSIBLE PARTNER (C. Bloom). Work suspended due to client budget freeze effective August 11, 2023. DO NOT FILE.
DEADLINE NOTE: The Office Action response deadline was originally three (3) months from the Office Action mailing date. A two-month Extension of Time was filed by Peter Vassiliev on September 6, 2023 (fee of $640.00, small entity rate). The absolute six-month statutory deadline for response under 37 C.F.R. § 1.136(a) is March 9, 2025. No further extensions of time are available under 37 C.F.R. § 1.136(a). Failure to file a response by March 9, 2025 will result in abandonment of U.S. Application No. 17/672,204.
RESPONSE TO NON-FINAL OFFICE ACTION
IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
RESPONSE TO NON-FINAL OFFICE ACTION
Commissioner for Patents United States Patent and Trademark Office P.O. Box 1450 Alexandria, VA 22313-1450
Dear Commissioner:
Applicant Optiwave Semiconductor Corp. ("Applicant" or "OWS"), by and through its undersigned attorneys of record at Calderwood & Harkness LLP, hereby respectfully submits this Response to the Non-Final Office Action in the above-identified application. Applicant requests entry of the amendments and consideration of the remarks set forth herein.
I. PRELIMINARY REMARKS
Applicant respectfully submits this Response to the Non-Final Office Action mailed in the above-identified application (the "Office Action"). The mailing date of the Office Action is to be confirmed from the prosecution file maintained by the United States Patent and Trademark Office ("USPTO").
Applicant Optiwave Semiconductor Corp. respectfully requests that the Examiner consider the amendments to the claims and the supporting remarks set forth below, and that all pending rejections be reconsidered and withdrawn in view thereof.
A two-month Extension of Time was filed with the USPTO on September 6, 2023, accompanied by the requisite fee of $640.00 (small entity rate), by Peter Vassiliev of Calderwood & Harkness LLP. Accordingly, this Response is timely filed within the extended period for response.
This application, U.S. Application No. 17/672,204, was filed on January 9, 2023, and claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/297,841, filed January 10, 2022. The provisional application expired on January 10, 2023, and priority thereto has been preserved through the timely filing of the present non-provisional application on January 9, 2023, one day prior to the expiration of the twelve-month period for claiming priority under 35 U.S.C. § 119(e).
Calderwood & Harkness LLP is the attorney of record for Applicant in this matter. All correspondence should be directed to:
Calderwood & Harkness LLP
Attn: Intellectual Property Group
555 California Street, 42nd Floor San Francisco, CA 94104
This Response has been prepared by Christy Bauer (USPTO Reg. No. 74,329), Lead Associate, intellectual Property Group, Calderwood & Harkness LLP. Catherine Bloom (USPTO Reg. No. 58,412), Partner, serves as the responsible partner for this prosecution matter.
II. STATUS OF THE CLAIMS PRIOR TO AMENDMENT
The claims of U.S. Application No. 17/672,204 were originally filed on January 9, 2023, as part of the non-provisional application. As filed, the application contained a total of twenty-four (24) claims, numbered Claims 1 through 24, comprising three (3) independent claims and twenty-one (21) dependent claims.
The independent claims are directed to the following subject matter:
Claim 1 is directed to a multi-channel silicon-photonic Mach-Zehnder modulator apparatus comprising a segmented traveling-wave electrode architecture. Claim 1 recites the structural elements of the modulator, including the photonic waveguide structure, the Mach-Zehnder interferometer arms, and the segmented traveling-wave electrode configuration. Claims 2 through 11 depend from Claim 1 and recite additional structural and functional features of the apparatus.
Claim 12 is directed to a method of modulating optical signals using the multi-channel silicon-photonic Mach-Zehnder modulator. Claim 12 recites steps for receiving an input optical signal, splitting the signal into a plurality of channels, applying modulation via the segmented traveling-wave electrode architecture, and combining the modulated signals for output. Claims 13 through 17 depend from Claim 12 and recite additional method steps and parameters.
Claim 18 is directed to an integrated photonic circuit system for data-center optical interconnects incorporating the multi-channel silicon-photonic Mach-Zehnder modulator with segmented traveling-wave electrode architecture. Claim 18 recites the system-level context in which the modulator operates, including the optical transceiver module, the photonic integrated circuit substrate, and the electronic driver circuitry. Claims 19 through 24 depend from Claim 18 and recite additional system-level features and specifications.
No amendments to the claims have been entered prior to this Response. The claims as originally filed are the claims that were examined in the Office Action.
The Office Action rejected certain of the claims under 35 U.S.C. § 102 (anticipation) and 35 U.S.C. § 103 (obviousness), citing as primary references two United States patents owned by Pinnacle Optics, Inc.: U.S. Patent No. 10,823,417, issued November 3, 2020 (hereinafter, the "'417 patent"); and U.S. Patent No. 11,105,662, issued August 31, 2021 (hereinafter, the "'662 patent"). The specific rejections are summarized in Section III below.
III. SUMMARY OF THE OFFICE ACTION REJECTIONS
The Office Action sets forth rejections of certain claims under 35 U.S.C. §§ 102 and 103. Applicant summarizes these rejections below for the convenience of the Examiner and to provide context for the amendments and arguments presented in Sections IV and V of this Response.
A. Rejections Under 35 U.S.C. § 102(a)(1) — Anticipation
The Office Action rejected Claims 1, 2, 3, 5, 7, 12, 13, 18, and 19 under 35 U.S.C. § 102(a)(1) as being anticipated by U.S. Patent No. 10,823,417 (the '417 patent), assigned to Pinnacle Optics, Inc., and issued November 3, 2020.
The Examiner took the position that the '417 patent discloses a silicon-photonic Mach-Zehnder modulator incorporating a segmented traveling-wave electrode structure, and that each element of the rejected claims is expressly disclosed in the '417 patent. Specifically, the Examiner provided a claim-element mapping in which the '417 patent's description of a multi-segment electrode array for velocity-matched modulation in a silicon photonic platform was mapped to the claimed "segmented traveling-wave electrode architecture." The Examiner further mapped the '417 patent's disclosure of a multi-channel waveguide arrangement to the claimed "multi-channel" modulator configuration, and the '417 patent's Mach-Zehnder interferometric modulation scheme to the claimed Mach-Zehnder modulator structure.
The Examiner's claim chart identified specific columns and lines of the '417 patent as corresponding to each element of the rejected claims. Applicant addresses the specifics of this mapping in Section V.B below.
B. Rejections Under 35 U.S.C. § 103 — Obviousness
The Office Action rejected Claims 4, 6, 8, 9, 10, 11, 14, 15, 16, 17, 20, 21, 22, 23, and 24 under 35 U.S.C. § 103 as being unpatentable over U.S. Patent No. 10,823,417 (the '417 patent) in view of U.S. Patent No. 11,105,662 (the '662 patent), also assigned to Pinnacle Optics, Inc., and issued August 31, 2021.
The Examiner reasoned that it would have been obvious to a person of ordinary skill in the art at the time of the invention to combine the teachings of the '417 patent with those of the '662 patent. The '662 patent is directed to electrode fabrication processes for silicon-photonic modulators, including methods of forming segmented electrode structures on silicon-on-insulator (SOI) substrates. The Examiner asserted that a person of ordinary skill in the art would have been motivated to combine the '417 patent's modulator architecture with the '662 patent's fabrication techniques and additional electrode design parameters to arrive at the subject matter of the dependent claims, with a reasonable expectation of success.
The Examiner also cited additional secondary references in connection with certain dependent claims, including references directed to traveling-wave electrode design for high-speed electro-optic modulators, impedance matching in RF electrode structures, and silicon photonic integration techniques for data-center applications. Applicant will address each of these additional references in Section V.D below.
C. Any Other Rejections or Objections
[Draft note — CB: Review the Office Action for any claim objections (e.g., informalities, antecedent basis issues), specification objections, or drawing objections. If any such objections were raised, they should be summarized here and addressed in the amendments and/or remarks below. PENDING — to be completed upon full review of the Office Action.]
To the extent the Office Action raised any objections to the claims, specification, or drawings on the basis of informalities or other non-substantive grounds, Applicant addresses those matters below and makes any necessary corrections in the amendments set forth herein.
IV. AMENDMENTS TO THE CLAIMS
Applicant hereby amends the claims as set forth below. Additions to the claim language are indicated by underlining; deletions are indicated by strikethrough. The claims not listed below remain as previously presented.
A. Amended Independent Claim 1
Claim 1 (Currently Amended):
A multi-channel silicon-photonic Mach-Zehnder modulator apparatus, comprising:
(a) a silicon-on-insulator substrate having a plurality of optical waveguide channels formed thereon;
(b) a Mach-Zehnder interferometer structure for each of the plurality of optical waveguide channels, each Mach-Zehnder interferometer structure comprising a first arm and a second arm configured to receive and recombine portions of an input optical signal;
(c) a segmented traveling-wave electrode architecture disposed along at least one arm of each Mach-Zehnder interferometer structure, the segmented traveling-wave electrode architecture comprising a plurality of electrode segments electrically coupled in series along a propagation direction of the traveling-wave electrode,  and
(d) a radio-frequency signal input configured to apply a modulating electrical signal to the segmented traveling-wave electrode architecture for modulating the optical signal propagating through each Mach-Zehnder interferometer structure.
The key amendment to Claim 1 is the addition of the tapered impedance-matching region as a structural limitation of each electrode segment within the segmented traveling-wave electrode architecture. This amendment specifies that the electrode segments are not uniform at their interfaces but instead incorporate a tapered impedance-matching region that provides a graduated impedance transition between adjacent segments. The taper geometry is defined by a monotonic variation in at least one physical dimension — electrode width, electrode gap spacing, or electrode thickness — along the tapered impedance-matching region. This feature is a specific, structural design-around element that distinguishes the claimed invention from the uniform, non-tapered segment interfaces disclosed in the Pinnacle Optics '417 patent.
As noted herein, this design-around feature was the principal point of distinction identified in the Calderwood & Harkness LLP freedom-to-operate analysis delivered to Optiwave Semiconductor Corp. on October 14, 2022, and forms the basis of OWS's differentiated modulator product architecture.
B. Amended Independent Claim 12
Claim 12 (Currently Amended):
A method of modulating optical signals using a multi-channel silicon-photonic Mach-Zehnder modulator, the method comprising:
(a) receiving an input optical signal at a silicon-on-insulator photonic integrated circuit comprising a plurality of optical waveguide channels;
(b) splitting the input optical signal into a plurality of channel signals, each channel signal directed along a respective Mach-Zehnder interferometer structure comprising a first arm and a second arm;
(c) applying a modulating electrical signal to a segmented traveling-wave electrode architecture disposed along at least one arm of each Mach-Zehnder interferometer structure, the segmented traveling-wave electrode architecture comprising a plurality of electrode segments electrically coupled in series along a propagation direction, 
(d) modulating each of the plurality of channel signals by electro-optic interaction between the modulating electrical signal and the optical signal in at least one arm of the Mach-Zehnder interferometer structure; and
(e) recombining the modulated channel signals to produce a modulated output optical signal.
The amendment to Claim 12 introduces a corresponding method step specifying that the modulating electrical signal propagates through the tapered impedance-matching region between adjacent electrode segments, with the graduated impedance transition defined by the same structural parameters recited in amended Claim 1. The amendment maintains parallel structure with Claim 1 and ensures that the method claim captures the functional operation of the tapered impedance-matching feature.
C. Amended Independent Claim 18
Claim 18 (Currently Amended):
An integrated photonic circuit system for data-center optical interconnects, the system comprising:
(a) an optical transceiver module configured for operation at data rates of at least 800 Gbps per module;
(b) a photonic integrated circuit disposed within the optical transceiver module, the photonic integrated circuit comprising a silicon-on-insulator substrate;
(c) a multi-channel silicon-photonic Mach-Zehnder modulator formed on the photonic integrated circuit, the Mach-Zehnder modulator comprising:
(i) a plurality of optical waveguide channels;
(ii) a Mach-Zehnder interferometer structure for each of the plurality of optical waveguide channels; and
(iii) a segmented traveling-wave electrode architecture disposed along at least one arm of each Mach-Zehnder interferometer structure, the segmented traveling-wave electrode architecture comprising a plurality of electrode segments electrically coupled in series, 
(d) electronic driver circuitry electrically coupled to the segmented traveling-wave electrode architecture and configured to generate modulating electrical signals at a symbol rate supporting per-channel data rates of at least 100 Gbps per channel; and
(e) an output optical interface configured to couple the modulated optical signals from the photonic integrated circuit to an optical fiber for data-center interconnect transmission .
The amendment to Claim 18 incorporates the tapered impedance-matching feature at the system level, consistent with the amendments to Claims 1 and 12. In addition, Claim 18 has been amended to further specify the data-center interconnect context, including express recitation of compatibility with 800G and 1.6T optical transceiver standards, reflecting the intended commercial application of OWS's modulator technology.
D. Amendments to Dependent Claims
Applicant has reviewed the dependent claims (Claims 2–11, 13–17, and 19–24) and does not believe that conforming amendments to the existing dependent claims are required at this time, as the dependent claims incorporate the limitations of the independent claims by reference and will automatically reflect the amendments to Claims 1, 12, and 18.
[Draft note — CB: Consider adding 2–3 new dependent claims narrowing the taper geometry with specific parameters. Potential new claims could recite:
•  A specific impedance gradient range (e.g., an impedance transition of between 5 Ω and 15 Ω over a taper length of between 50 μm and 200 μm);
•  A specific taper angle or taper profile (e.g., a linear taper profile or an exponential taper profile);
•  Specific materials for the tapered region (e.g., doped silicon, aluminum, copper, or gold electrode materials with specified resistivity ranges).
Need to discuss with Dr. Lena Strickland regarding preferred embodiment parameters and the specific taper geometries that have been fabricated and tested in OWS's production devices. PENDING.]
Applicant reserves the right to propose additional dependent claims directed to specific tapered impedance-matching parameters in a subsequent filing or supplemental response, if appropriate.
V. REMARKS IN SUPPORT OF PATENTABILITY
A. Overview of Amendments and Argument Strategy
The amendments set forth in Section IV above add the tapered impedance-matching feature as a structural limitation to each of the three independent claims (Claims 1, 12, and 18). This feature — specifying that each electrode segment comprises a tapered impedance-matching region configured to provide a graduated impedance transition between adjacent segments — is a critical structural distinction that differentiates the claimed invention from the prior art cited in the Office Action.
The tapered impedance-matching feature is fully supported by the specification as filed on January 9, 2023. Specifically, the as-filed specification describes the tapered impedance-matching region in detail at paragraphs [0047]–[0055], with reference to Figures 5A, 5B, 6, and 7. Figure 5A depicts a schematic plan view of the segmented traveling-wave electrode architecture showing the tapered impedance-matching regions at the interfaces between adjacent electrode segments. Figure 5B provides a magnified view of a single tapered impedance-matching region, illustrating the monotonic variation in electrode width along the taper. Figure 6 presents a graph of the impedance profile along the length of the segmented electrode, showing the graduated impedance transitions at each taper. Figure 7 depicts an alternative embodiment in which the impedance transition is effectuated by variation in electrode gap spacing rather than electrode width.
No new matter has been introduced by the amendments. All claim limitations added by the amendments find express support in the specification as originally filed, in full compliance with 35 U.S.C. § 132 and 37 C.F.R. § 1.121. Applicant submits that the amendments are proper under the patent rules and that no new matter rejection is warranted.
Applicant respectfully submits that the amendments to Claims 1, 12, and 18, as described above, overcome all outstanding rejections under 35 U.S.C. §§ 102 and 103. The detailed arguments in support of this position are set forth in Sections V.B and V.C below.
B. Traversal of § 102 Rejection — Anticipation by the '417 Patent
Applicant respectfully traverses the rejection of Claims 1, 2, 3, 5, 7, 12, 13, 18, and 19 under 35 U.S.C. § 102(a)(1) as anticipated by U.S. Patent No. 10,823,417 (the '417 patent, Pinnacle Optics, Inc.).
To anticipate a claim under § 102, a single prior art reference must disclose each and every element of the claimed invention, arranged as in the claim, either expressly or inherently. Verdegaal Bros., Inc. v. Union Oil Co. of Cal., 814 F.2d 628, 631 (Fed. Cir. 1987). The Federal Circuit has consistently held that "[t]he identical invention must be shown in as complete detail as is contained in the ... claim." Richardson v. Suzuki Motor Co., 868 F.2d 1226, 1236 (Fed. Cir. 1989). There is no room under the anticipation standard for combining elements from different embodiments or for supplying missing elements through inference; the reference must teach each element either explicitly or inherently. Atofina v. Great Lakes Chem. Corp., 441 F.3d 991, 999 (Fed. Cir. 2006).
The '417 patent does not disclose the newly claimed tapered impedance-matching region. Applicant provides the following detailed element-by-element analysis, which is based in part on the claim chart prepared by Christy Bauer in October 2022 comparing the OWS pending claims against the Pinnacle '417 patent (referenced in the C&H freedom-to-operate analysis delivered October 14, 2022).
Element-by-Element Comparison:
The '417 patent discloses a silicon-photonic Mach-Zehnder modulator with a segmented traveling-wave electrode structure. This much is not disputed. However, the critical distinction lies in the nature of the electrode segment interfaces. The '417 patent describes an electrode architecture in which adjacent electrode segments are connected at uniform, non-tapered interfaces. The '417 patent repeatedly emphasizes that each electrode segment has a substantially constant characteristic impedance along its length, and that the interfaces between adjacent segments are designed to maintain impedance uniformity across the entire electrode array.
Specifically, the '417 patent states:
"Each electrode segment is designed to have a substantially uniform cross-sectional profile along its length, providing a consistent characteristic impedance of approximately 50 Ω throughout the segmented electrode array." ('417 patent, col. 8, ll. 32–37.)
"The interfaces between adjacent electrode segments are configured to minimize discontinuities in the electrode cross-section, thereby maintaining impedance uniformity and reducing signal reflections at segment boundaries." ('417 patent, col. 9, ll. 5–10.)
These passages confirm that the '417 patent's electrode segmentation geometry is predicated on uniform impedance at the segment interfaces — the opposite of the tapered, graduated impedance transition claimed by OWS. There is no disclosure, suggestion, or teaching anywhere in the '417 patent of a tapered impedance-matching region at the segment interfaces. The '417 patent does not describe any monotonic variation in electrode width, electrode gap spacing, or electrode thickness at or near the segment interfaces.
Applicant has reviewed all embodiments, figures, and descriptions in the '417 patent. None of the disclosed embodiments includes a tapered impedance-matching region. The '417 patent's Figures 3, 4A, and 4B depict the electrode segments with abrupt, rectangular transitions at the segment boundaries. The '417 patent's specification does not use the terms "taper," "tapered," "impedance-matching region," "graduated impedance," "impedance transition," or any equivalent terminology.
Because the tapered impedance-matching region is a distinct structural element that is entirely absent from any embodiment of the '417 patent, the '417 patent cannot anticipate the amended claims. The § 102(a)(1) anticipation rejection should therefore be withdrawn with respect to all claims.
Conclusion: The amended claims recite a tapered impedance-matching region that is not disclosed, taught, or suggested by the '417 patent. Each of the independent claims as amended includes this element as a structural limitation. Because the '417 patent fails to disclose each and every element of the amended claims, the rejection under 35 U.S.C. § 102(a)(1) is overcome. Applicant respectfully requests that the Examiner withdraw this rejection.
C. Traversal of § 103 Rejection — Obviousness over the '417 Patent in View of the '662 Patent
Applicant respectfully traverses the rejection of Claims 4, 6, 8, 9, 10, 11, 14, 15, 16, 17, 20, 21, 22, 23, and 24 under 35 U.S.C. § 103 as being unpatentable over U.S. Patent No. 10,823,417 (the '417 patent) in view of U.S. Patent No. 11,105,662 (the '662 patent), both assigned to Pinnacle Optics, Inc.
A claim is unpatentable under § 103 only if the differences between the claimed subject matter and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art. 35 U.S.C. § 103. The Supreme Court has established that the obviousness inquiry requires consideration of (1) the scope and content of the prior art, (2) the differences between the prior art and the claimed invention, (3) the level of ordinary skill in the pertinent art, and (4) any objective indicia of non-obviousness. Graham v. John Deere Co., 383 U.S. 1, 17–18 (1966). Furthermore, there must be "some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007) (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)).
The '662 Patent Does Not Disclose or Suggest the Tapered Impedance-Matching Region.
The '662 patent is directed to electrode fabrication processes for silicon-photonic modulators, including methods of forming segmented electrode structures on silicon-on-insulator (SOI) substrates. While the '662 patent addresses various aspects of electrode fabrication — including metal deposition techniques, lithographic patterning of electrode segments, and post-fabrication impedance tuning — it does not disclose or suggest a tapered impedance-matching region between adjacent electrode segments.
The '662 patent's fabrication methods are directed to producing electrode segments with uniform cross-sectional profiles, consistent with the design philosophy articulated in the '417 patent. The '662 patent does not describe any process step for forming a taper or graduated transition region at the electrode segment interfaces. There is no suggestion in the '662 patent that impedance matching between adjacent segments should be achieved through a tapered geometry rather than through uniform electrode design.
Accordingly, even when considered in combination, the '417 patent and the '662 patent do not teach or suggest the tapered impedance-matching region recited in the amended claims.
Lack of Motivation to Combine.
Even assuming arguendo that the individual references could somehow be read to collectively disclose the claimed elements (which Applicant does not concede), the Examiner has not articulated a proper motivation to combine the references in a manner that would arrive at the claimed tapered impedance-matching feature. Neither the '417 patent nor the '662 patent suggests that the uniform segment interfaces should be replaced with a tapered impedance-matching region. To the contrary, both references are consistent in their emphasis on maintaining impedance uniformity across the electrode array. There is no suggestion in either reference that impedance non-uniformity at the segment interfaces would be desirable, and no disclosure of a tapered geometry as a means of achieving impedance matching.
The Examiner's motivation to combine the references appears to be based on the general proposition that a person of ordinary skill would look to the '662 patent's fabrication techniques to manufacture the modulator of the '417 patent. However, this reasoning does not account for the specific tapered impedance-matching feature, which is not taught by either reference individually or in combination. The mere fact that two references share a common technological field does not establish a motivation to combine them in a manner that produces the specific claimed invention. In re Rouffet, 149 F.3d 1350, 1357–58 (Fed. Cir. 1998).
Teaching Away.
The '417 patent affirmatively teaches away from the tapered impedance-matching approach recited in the amended claims. As discussed in Section V.B above, the '417 patent repeatedly emphasizes uniform segment impedance as a design goal. The '417 patent expressly states that "the interfaces between adjacent electrode segments are configured to minimize discontinuities in the electrode cross-section, thereby maintaining impedance uniformity" ('417 patent, col. 9, ll. 5–10). This design philosophy is fundamentally inconsistent with the claimed tapered impedance-matching region, which intentionally introduces a spatially varying impedance profile at each segment interface.
A reference that "teaches away" from the claimed invention — i.e., that "criticize[s], discredit[s], or otherwise discourage[s]" the claimed approach — weighs against a finding of obviousness. In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004). The '417 patent's emphasis on impedance uniformity constitutes a teaching away from the non-uniform, tapered impedance approach of the present invention. A person of ordinary skill in the art, reading the '417 patent, would have been led in the opposite direction from the claimed invention — toward uniform segment interfaces rather than toward graduated impedance transitions.
Secondary Considerations of Non-Obviousness.
Applicant further submits that objective indicia of non-obviousness support the patentability of the amended claims. The Supreme Court has recognized that secondary considerations — including commercial success, long-felt but unresolved need, and failure of others — are relevant to the obviousness inquiry and "may often be the most probative and cogent evidence" of non-obviousness. Graham v. John Deere Co., 383 U.S. at 17–18.
Commercial Success. OWS has achieved commercial success with products incorporating the tapered impedance-matching feature claimed in the present application. OWS's design-around modulator architecture, which employs the tapered impedance-matching electrode geometry, has been incorporated into OWS's 800G optical transceiver product line and has generated substantial commercial revenue.
[Draft note — CB: Need to gather supporting evidence from Dr. Lena Strickland and Dr. Feng-Yi Chen on commercial performance data. Also need to verify FY 2022/2023 product revenue attributable to the design-around architecture. OWS FY 2022 revenue was $68.1M; FY 2023 revenue was $47.3M (down due to sector downturn, not product issue). Need to establish a nexus between the commercial success and the specific tapered impedance-matching feature. Consider requesting a declaration from Dr. Strickland or Sandra Koh (OWS IP Manager) in support. PENDING.]
Long-Felt But Unresolved Need. There exists a long-felt but unresolved need in the silicon photonics industry for improved signal integrity at high data rates (800G and 1.6T) in silicon-photonic modulators. The transition from 400G to 800G and 1.6T data rates has exposed significant signal integrity challenges at electrode segment boundaries in conventional segmented traveling-wave electrode designs. The tapered impedance-matching feature of the present invention directly addresses this need by reducing signal reflections and improving the quality of the modulating RF signal along the electrode.
[Draft note — CB: Need to identify and cite industry publications documenting this long-felt need. Consider citing IEEE/OSA publications on signal integrity challenges in high-speed silicon photonic modulators. Also consider citing OFC (Optical Fiber Communication Conference) proceedings from 2020–2022 discussing electrode design challenges at 800G data rates. PENDING.]
Conclusion: The combination of the '417 patent and the '662 patent does not render the amended claims obvious. Neither reference discloses or suggests the tapered impedance-matching region. There is no motivation to combine the references to arrive at the claimed feature. The '417 patent teaches away from the claimed approach. And secondary considerations — including commercial success and long-felt but unresolved need — support a finding of non-obviousness. Applicant respectfully requests that the Examiner withdraw the § 103 rejection.
D. Distinction of Additional Secondary References
[Draft note — CB: This section is incomplete. Need to review all secondary references cited by the Examiner in the Office Action and draft individualized arguments distinguishing each reference from the amended claims. Each secondary reference should be analyzed for whether it discloses or suggests the tapered impedance-matching feature, and arguments should be provided as to why the secondary references, individually or in combination with the primary references, do not render the amended claims obvious. PENDING PARTNER REVIEW AND CLIENT INPUT.]
Applicant will provide additional arguments addressing each secondary reference cited by the Examiner in the Office Action. To the extent any secondary reference is asserted to disclose an impedance-matching feature, Applicant will demonstrate that such disclosure, if any, is materially different from the specific tapered impedance-matching region recited in the amended claims.
E. Support in the Specification for Amended Claims
Applicant confirms that all limitations added by the amendments to Claims 1, 12, and 18 are fully supported by the specification as originally filed on January 9, 2023, in U.S. Application No. 17/672,204.
The tapered impedance-matching feature is described in detail in the following sections of the as-filed specification:
•  Paragraphs [0047]–[0049]: General description of the tapered impedance-matching region and its function in providing a graduated impedance transition between adjacent electrode segments, including the design rationale for reducing RF signal reflections and improving modulation bandwidth.
•  Paragraph [0050]: Description of the monotonic variation in electrode width as one mechanism for achieving the impedance taper, including specific dimensional ranges for the taper length (50 μm to 200 μm) and the impedance transition (from approximately 45 Ω to 55 Ω over the taper length in the preferred embodiment).
•  Paragraphs [0051]–[0052]: Alternative embodiments in which the impedance transition is effectuated by variation in electrode gap spacing or electrode thickness, or by a combination of geometric parameters.
•  Paragraphs [0053]–[0055]: Simulation results and experimental data demonstrating the performance advantages of the tapered impedance-matching region, including reduced return loss (S11) and improved electro-optic bandwidth compared to conventional uniform segment interfaces.
•  Figure 5A: Schematic plan view of the segmented traveling-wave electrode architecture showing the tapered impedance-matching regions at each segment interface.
•  Figure 5B: Magnified view of a single tapered impedance-matching region, showing the monotonic variation in electrode width along the taper.
•  Figure 6: Graph of the impedance profile along the length of the segmented electrode, illustrating the graduated impedance transitions at each taper.
•  Figure 7: Alternative embodiment with impedance transition effectuated by variation in electrode gap spacing.
Applicant confirms that the amended claims comply with the written description and enablement requirements of 35 U.S.C. § 112(a). The specification provides a clear, complete description of the tapered impedance-matching feature that demonstrates that the inventors were in possession of the claimed invention at the time of filing. The specification further enables a person of ordinary skill in the art to make and use the claimed invention without undue experimentation.
[Draft note — CB: Need to cross-check the specification paragraphs referenced above against the U.S. Provisional Application No. 63/297,841, filed January 10, 2022, by Kessler & Morin LLP (the provisional was drafted by Dr. Helen Kessler at K&M). The purpose of this cross-check is to confirm that the tapered impedance-matching limitation has priority support in the provisional application, such that the effective filing date for the amended claims is January 10, 2022 (the provisional filing date) rather than January 9, 2023 (the non-provisional filing date). If the tapered impedance-matching feature is not described in the provisional, the effective filing date for the amended claims may be the non-provisional filing date of January 9, 2023, which could affect the prior art landscape. PENDING.]
VI. CONCLUSION
In view of the foregoing amendments and remarks, Applicant respectfully submits that all pending claims as amended are in condition for allowance. Applicant requests that the Examiner reconsider and withdraw all rejections set forth in the Non-Final Office Action, including the rejections under 35 U.S.C. §§ 102 and 103.
If the Examiner believes that any issue remains unresolved after consideration of this Response, Applicant respectfully requests an interview with the Examiner to discuss the claims and the prior art. Catherine Bloom (Reg. No. 58,412) and Christy Bauer (Reg. No. 74,329) are available for an interview at the Examiner's convenience, and can be reached at the telephone number set forth below.
Applicant believes that all claims as amended are patentable over the cited prior art and respectfully requests favorable action on this application.
VII. SIGNATURE BLOCK
[DRAFT — Signature placeholder. Not yet executed. This Response is to be signed by Catherine Bloom (Reg. No. 58,412), responsible partner, upon completion of partner review. DO NOT FILE without partner signature.]
Respectfully submitted,
CALDERWOOD & HARKNESS LLP
By: ________
Catherine Bloom (Reg. No. 58,412) Partner, intellectual Property Group
Christy Bauer (Reg. No. 74,329) Lead Associate, intellectual Property Group
555 California Street, 42nd Floor San Francisco, CA 94104 Telephone: [To be confirmed]
Email: [To be confirmed]
Date: ________
VIII. CERTIFICATE OF SERVICE / CERTIFICATE OF MAILING
CERTIFICATE OF ELECTRONIC FILING
I hereby certify that this Response to Non-Final Office Action, together with all accompanying papers and amendments, is being filed electronically via the USPTO Patent Center electronic filing system on the date indicated below, in accordance with 37 C.F.R. § 1.6(a)(4).
By: ________
Name: ________
Registration No.: ________
Date: ________
[Draft note: Certificate of electronic filing has not yet been populated. To be completed upon finalization of the Response and authorization to file. Filing will be accomplished via Patent Center (formerly EFS-Web). Confirm filing receipt number and timestamp upon submission.]
APPENDIX: INCOMPLETE WORK / OPEN ITEMS LOG
PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT — NOT FOR FILING This Appendix is an internal tracking document of Calderwood & Harkness LLP and is subject to the attorney-client privilege and the attorney work product doctrine. This Appendix is not part of the Response to be filed with the USPTO. It is maintained for internal case management purposes only and must not be transmitted to the client, filed with the USPTO, or disclosed to any third party without prior authorization from Catherine Bloom.
C&H Matter No.: 1014-00005 Application No.: 17/672,204 Status as of: August 28, 2023
Open Items:
1.  Partner Review by Catherine Bloom — NOT YET CONDUCTED. Draft v0.3 of this Response has not been reviewed by the responsible partner, Catherine Bloom (Reg. No. 58,412). Partner review is required before this Response may be finalized or filed. Work on this matter was suspended effective August 11, 2023, due to the client budget freeze (see Item 9 below).
2.  Client Review by Sandra Koh (OWS IP Manager) — NOT YET SENT. The draft Response has not been transmitted to the client for review. Sandra Koh, IP Manager at Optiwave Semiconductor Corp., is the designated client contact for prosecution matters. Client review and approval are required before filing. The draft should not be sent to the client until partner review is completed.
3.  Technical Verification with Dr. Lena Strickland and Dr. Feng-Yi Chen Regarding Taper Geometry Parameters — PENDING. The specific taper geometry parameters (e.g., taper length, impedance gradient, taper profile) recited in the amended claims should be verified against the preferred embodiment parameters used in OWS's production devices. Dr. Strickland (lead inventor) and Dr. Chen (co-inventor and fabrication lead) are the appropriate technical contacts. This verification is necessary before finalizing the claim amendments and before considering whether to propose new dependent claims directed to specific taper parameters.
4.  Cross-Check of Priority Support in Provisional Application No. 63/297,841 (Originally Drafted by Kessler & Morin LLP) — PENDING. The tapered impedance-matching limitation added by the amendments must be cross-checked against the disclosure of the provisional application to confirm that priority support exists. The provisional was drafted by Dr. Helen Kessler at Kessler & Morin LLP ("K&M") and filed January 10, 2022. If the tapered impedance-matching feature is not described in the provisional, the effective filing date for the amended claims would be the non-provisional filing date of January 9, 2023, which could affect the prior art analysis. C&H should obtain a copy of the provisional specification from K&M or from the prosecution file and conduct a detailed comparison.
5.  Secondary Considerations Evidence Gathering (Commercial Success Data) — PENDING. Evidence of commercial success of OWS's design-around products incorporating the tapered impedance-matching feature is needed to support the secondary considerations argument in Section V.C. Relevant data includes: (a) FY 2022 and FY 2023 revenue attributable to products incorporating the design-around architecture; (b) customer adoption data for OWS's 800G transceiver modules; (c) any industry recognition or awards for the design-around technology. Note: OWS FY 2022 total revenue was $68.1M; FY 2023 total revenue was $47.3M (the decline is attributable to the broader semiconductor sector downturn and is not indicative of product performance issues). Revenue attributable specifically to the design-around architecture has not yet been disaggregated. A declaration from Dr. Strickland or Sandra Koh may be necessary to establish the nexus between commercial success and the claimed features.
6.  Individualized Arguments for Each Examiner-Cited Secondary Reference — NOT DRAFTED. Section V.D of the Response (Distinction of Additional Secondary References) is incomplete. Each secondary reference cited by the Examiner must be reviewed and distinguished individually. This task cannot be completed until the full Office Action has been reviewed and all cited references have been obtained and analyzed.
7.  Decision on Whether to File RCE If Amendments Are Deemed to Change Scope. If the Examiner determines that the amendments to the independent claims change the scope of the claims such that a Request for Continued Examination (RCE) is required, the estimated cost is $2,000 in USPTO fees at the small entity rate, in addition to approximately 40–55 attorney hours for preparing the RCE and any supplemental response. At the blended discounted rates applicable to the OWS engagement, this represents approximately $22,000–$30,000 in total professional fees, exclusive of USPTO fees. This expenditure would require separate budget authorization from the client, which is currently subject to the budget freeze (see Item 9).
8.  Confirm Whether New Dependent Claims Should Be Added — Requires Discussion with Prosecution Strategy Team. As noted in Section IV.D, consideration should be given to adding 2–3 new dependent claims narrowing the taper geometry with specific parameters. This decision should be made in consultation with the prosecution strategy team (Catherine Bloom, Christy Bauer, and Peter Vassiliev) and with input from the inventors (Dr. Strickland and Dr. Chen).
9.  Budget Authorization — All Work Suspended as of August 11, 2023. All work on this matter has been suspended effective August 11, 2023, pursuant to the Project Lighthouse budget freeze imposed by Harborview Partners (OWS's majority equity investor). The quarterly IP spend has been capped at $25,000 per quarter, compared to a pre-freeze average of approximately $87,400 per quarter. The current matter (C&H Matter No. 1014-00005) has an outstanding balance of fees and costs that must be reconciled against the quarterly cap. No further work should be performed on this matter without express written authorization from Sandra Koh (OWS) or direction from Catherine Bloom, following confirmation that budget has been allocated.
10.  Absolute Deadline — March 9, 2025. The absolute deadline to file this Response is March 9, 2025. No further extensions of time are available under 37 C.F.R. § 1.136(a). A two-month extension of time was purchased on September 6, 2023, at a cost of $640.00 (small entity rate). If the Response is not filed by March 9, 2025, U.S. Application No. 17/672,204 will be ABANDONED. Abandonment would result in the irrevocable loss of the foundational U.S. patent application for OWS's core modulator architecture and the tapered impedance-matching design-around claim scope. Per the C&H freedom-to-operate analysis delivered October 14, 2022, loss of this application would leave OWS at "moderate-to-high" infringement risk vis-à-vis Pinnacle Optics' '417 patent (U.S. Patent No. 10,823,417) with no defensive patent position. This risk assessment should be communicated to OWS's management and to Veltrano Capital Partners as part of any budget negotiation.
END OF APPENDIX — PRIVILEGED AND CONFIDENTIAL — ATTORNEY WORK PRODUCT
Application No.: | 17/672,204
Filing Date: | January 9, 2023
Title of Invention: | Multi-Channel Silicon-Photonic Mach-Zehnder Modulator with Segmented Traveling-Wave Electrode Architecture
Named Inventors: | Dr. Rajan Menon, Dr. Lena Strickland, Dr. Feng-Yi Chen, Dr. Arjun Dasgupta
Applicant/Assignee: | Optiwave Semiconductor Corp.
Confirmation No.: | [To be confirmed]
Art Unit: | [To be confirmed]
Examiner: | [To be confirmed]
Attorney Docket No.: | OWS-2022-A1
Customer No.: | [C&H customer number — to be confirmed]
Priority Claim: | Claims benefit of U.S. Provisional Application No. 63/297,841, filed January 10, 2022

RESPONSE TO NON-FINAL OFFICE ACTION

IN THE UNITED STATES PATENT AND TRADEMARK OFFICE

RESPONSE TO NON-FINAL OFFICE ACTION

I. PRELIMINARY REMARKS

II. STATUS OF THE CLAIMS PRIOR TO AMENDMENT

III. SUMMARY OF THE OFFICE ACTION REJECTIONS

IV. AMENDMENTS TO THE CLAIMS

V. REMARKS IN SUPPORT OF PATENTABILITY

VI. CONCLUSION

VII. SIGNATURE BLOCK

CALDERWOOD & HARKNESS LLP

VIII. CERTIFICATE OF SERVICE / CERTIFICATE OF MAILING

CERTIFICATE OF ELECTRONIC FILING

APPENDIX: INCOMPLETE WORK / OPEN ITEMS LOG

Record

Parties

Dates

Amounts