UNITED STATES DISTRICT COURT EASTERN DISTRICT OF TEXAS MARSHALL DIVISION
PLAINTIFF OPTIWAVE SEMICONDUCTOR CORP.'S REPLY CLAIM CONSTRUCTION BRIEF
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I. INTRODUCTION
Plaintiff Optiwave Semiconductor Corp. ("OWS") respectfully submits this Reply Claim Construction Brief in response to the Responsive Claim Construction Brief filed by Defendant Lumicore Technologies, Inc. ("Lumicore") on December 6, 2024 (D.E. 48). Lumicore's responsive brief, filed by its counsel Hawthorne Vega & Cruz LLP, asks this Court to adopt claim constructions that would improperly narrow the scope of four asserted patents by importing implementation-specific limitations drawn from preferred embodiments and selective extrinsic sources into claim terms that the intrinsic record—the claims, specification, and prosecution history—define far more broadly. The Court should decline Lumicore's invitation.
As set forth in the Joint Claim Construction Statement filed on October 28, 2024 (D.E. 40), the parties originally identified fourteen disputed claim terms across the four asserted patents in this case: U.S. Patent No. 10,234,847 (the "'847 Patent"), U.S. Patent No. 10,891,193 (the "'193 Patent"), U.S. Patent No. 9,678,562 (the "'562 Patent"), and U.S. Patent No. 11,402,015 (the "'015 Patent"). Following meet-and-confer efforts, the parties reached agreement on two of those terms, leaving twelve terms in dispute. This reply focuses on the four terms that present the most consequential disputes and where Lumicore's responsive brief advances constructions that are most clearly contradicted by the intrinsic record:
1. "Waveguide multiplexer" (the '847 Patent, Claims 1, 3, 5, 9, and 14) — Lumicore seeks to limit this term to a single species of multiplexer (an arrayed waveguide grating, or "AWG") despite the patent's express disclosure of multiple multiplexer architectures and despite dependent claim language that separately recites the AWG limitation.
2. "Integrated on a silicon substrate" (the '193 Patent, Claims 1, 3, 7, 10, 15, and 18) — Lumicore seeks to exclude hybrid integration and heterogeneous integration techniques, even though the specification expressly describes these approaches as embodiments of the claimed invention.
3. "Micro-channel heat sink" (the '562 Patent, Claims 1, 4, 6, and 11) — Lumicore attempts to import both a "closed-loop liquid-cooling" requirement and an artificially narrow upper bound on channel hydraulic diameter, neither of which appears in the claim language.
4. "Polarization-diverse grating coupler" (the '015 Patent, Claims 1, 5, 8, 12, and 16) — Lumicore improperly requires that the coupler use a "two-dimensional" grating with a separate "polarization-splitting element," despite the fact that dependent claims separately recite the two-dimensional limitation and the specification discloses inherent splitting embodiments.
A single overarching theme connects all four of Lumicore's proposed constructions: in each instance, Lumicore asks this Court to read into the claims a limitation drawn from a preferred embodiment or from a selective reading of extrinsic evidence, thereby narrowing the claims beyond what the patent language and specification support. This approach contravenes the Federal Circuit's en banc holding in Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005), which instructs that "[i]t is . . . not enough that the only embodiment, or all of the embodiments, contain a particular limitation" to justify importing that limitation into the claims. Id. at 1323. The approach is all the more improper here, where the specifications affirmatively disclose multiple embodiments without the limitations Lumicore seeks to impose.
Filed concurrently with this Reply is the Supplemental Declaration of Dr. Caroline Ashford (D.E. 53), Professor of Electrical Engineering and Photonics at the Northfield Institute of Technology in Evanston, Illinois. Dr. Ashford's Supplemental Declaration responds point-by-point to the opinions offered by Lumicore's expert, Dr. Rajesh Sundaram of Pacific Western University, as presented in Lumicore's responsive brief. As Dr. Ashford explains, Dr. Sundaram's opinions rest on an improperly narrow definition of a person of ordinary skill in the art ("POSITA") that was specifically tailored to predetermine the outcome of the claim construction analysis, and his proposed constructions are inconsistent with both the intrinsic record and the understanding of a properly defined POSITA.
OWS's Opening Claim Construction Brief (D.E. 44), filed on November 15, 2024, together with its supporting materials—including the Declaration of Dr. Caroline Ashford (D.E. 45), the Declaration of Dr. Jian-Wei Huang (D.E. 46), the Appendix of Intrinsic Evidence (D.E. 47), and the Appendix of Extrinsic Evidence (D.E. 48)—provides the full foundation for OWS's proposed constructions for all twelve disputed terms. This Reply does not repeat the full record but instead addresses the specific counterarguments raised in Lumicore's responsive brief. OWS respectfully reserves the right to present further argument at the Markman hearing scheduled for March 14, 2025 before this Court.
II. LEGAL STANDARD FOR CLAIM CONSTRUCTION
The parties agree on the basic framework for claim construction, and OWS therefore provides only a brief recitation of the governing legal standard for the Court's convenience.
Claim construction is a question of law for the Court. Markman v. Westview Instruments, Inc., 517 U.S. 370, 388–91 (1996). Where the district court's construction rests on the intrinsic evidence—the patent claims, specification, and prosecution history—the construction is reviewed de novo. Teva Pharm. USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 331 (2015). Where subsidiary factual findings underlie the construction, such as the resolution of disputes regarding the meaning of technical terms, those findings are reviewed for clear error. Id. at 332.
The words of a claim are generally given their "ordinary and customary meaning . . . [as] the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention." Phillips v. AWH Corp., 415 F.3d 1303, 1312–13 (Fed. Cir. 2005) (en banc). The inquiry into the ordinary meaning of claim terms is informed primarily by the intrinsic evidence. Id. at 1314. The claims themselves provide substantial guidance, because "the context in which a term is used in the asserted claim can be highly instructive." Id. The specification is "the single best guide to the meaning of a disputed term," as it "may reveal a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess" or "may reveal an intentional disclaimer, or disavowal, of claim scope by the inventor." Ridgeway & Co. v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996); Phillips, 415 F.3d at 1316. The prosecution history "can often inform the meaning of the claim language by demonstrating how the inventor understood the invention and whether the inventor limited the invention in the course of prosecution, making the claim scope narrower than it would otherwise be." Phillips, 415 F.3d at 1317.
A patentee may act as its own lexicographer, defining claim terms in a manner different from their ordinary meaning. Id. at 1316. However, the patentee's intent to deviate from ordinary meaning must be "clearly set forth" in the specification. Id. Absent a clear lexicographic definition, the ordinary meaning controls.
Extrinsic evidence—including expert testimony, inventor testimony, dictionaries, and learned treatises—may supplement the Court's understanding of claim terms but "is less significant than the intrinsic record in determining the legally operative meaning of claim language." Id. at 1317. Importantly, extrinsic evidence "may not be used to contradict claim meaning that is unambiguous in light of the intrinsic evidence." Id. at 1318.
Several corollary principles bear directly on the disputes at issue in this Reply:
First, limitations from preferred embodiments may not be imported into the claims. "[A]lthough the specification often describes very specific embodiments of the invention, [the Federal Circuit has] repeatedly warned against confining the claims to those embodiments." Phillips, 415 F.3d at 1323; see also Ashford Enterprises v. Dunmore Corporation, 358 F.3d 898, 906 (Fed. Cir. 2004) ("Even when the specification describes only a single embodiment, the claims of the patent will not be read restrictively unless the patentee has demonstrated a clear intention to limit the claim scope using words or expressions of manifest exclusion or restriction.") (internal quotation marks omitted).
Second, prosecution history estoppel may narrow claim scope, but only where there has been a "clear and unmistakable" disavowal of claim scope. Omega Eng'g, Inc. v. Raytek Corp., 334 F.3d 1314, 1325–26 (Fed. Cir. 2003). "[T]he standard for finding a disavowal or disclaimer in the prosecution history is . . . exacting, requiring 'clear and unmistakable' surrender of subject matter." Id. at 1325. Ambiguous statements during prosecution do not create estoppel. Id.
Third, the doctrine of claim differentiation creates a presumption that each claim in a patent differs in scope from every other claim. Phillips, 415 F.3d at 1314–15. "The presence of a dependent claim that adds a particular limitation gives rise to a presumption that the limitation in question is not present in the independent claim." Id. at 1315. While this presumption is not irrebuttable, it is "especially strong when the limitation in dispute is the only meaningful difference between an independent claim and a dependent claim." Pemberton Group v. Hollowell Industries, 483 F.3d 800, 806 (Fed. Cir. 2007). A construction that renders a dependent claim superfluous is disfavored. See Thorner v. Sony Computer Entm't Am. LLC, 669 F.3d 1362, 1367 (Fed. Cir. 2012).
With these principles in mind, OWS turns to the four critical disputed claim terms.
III. ARGUMENT
A. "Waveguide Multiplexer" ('847 Patent, Claims 1, 3, 5, 9, 14)
1. OWS's Proposed Construction (Restated). OWS proposes that the term "waveguide multiplexer" as used in the '847 Patent should be construed to mean: "an optical device that combines multiple optical signals of different wavelengths onto a single waveguide."
This construction reflects the ordinary and customary meaning of the term as it would be understood by a POSITA—an individual with a Master of Science or Ph.D. in electrical engineering or photonics and at least three years of experience in silicon-photonic integrated circuit ("IC") design—at the time of the invention. As set forth in OWS's Opening Brief and the accompanying Declaration of Dr. Ashford (D.E. 45), this construction is firmly grounded in the intrinsic record. The '847 Patent specification describes multiple embodiments of waveguide multiplexers, including but not limited to arrayed waveguide gratings ("AWGs"), echelle diffraction gratings, and Mach-Zehnder-based multiplexers. The construction captures the genus without limiting it to any single species.
Dr. Ashford's initial Declaration (D.E. 45) confirmed that a POSITA would understand "waveguide multiplexer" to be a term of art referring broadly to the class of on-chip optical devices that perform wavelength multiplexing via guided-wave structures, and the Supplemental Declaration of Dr. Ashford filed concurrently herewith (D.E. 53) further responds to the contrary opinions offered by Dr. Sundaram.
2. Lumicore's Improperly Narrow Construction. Lumicore proposes that "waveguide multiplexer" should be construed to mean: "an arrayed waveguide grating that combines optical signals using a slab coupler and phase-shifted waveguide array." Lumicore Responsive Br. at 8.
Lumicore's construction is deficient in multiple respects. Most fundamentally, it limits the claim term to a single species—the AWG—of a broader genus. The term "waveguide multiplexer" as used in Claim 1 of the '847 Patent is not modified by any language specifying an AWG architecture, a slab coupler, or a phase-shifted waveguide array. Lumicore's proposed construction adds each of these structural limitations—none of which appears in the claim language itself.
If adopted, Lumicore's construction would categorically exclude the echelle grating multiplexer embodiment described at column 4, lines 30–55 of the '847 Patent and the cascaded Mach-Zehnder interferometer multiplexer embodiment described at column 7, lines 12–38. Both of these embodiments are expressly disclosed in the specification as implementations of the "waveguide multiplexer" recited in the claims. Reading them out of the patent would directly violate the bedrock principle that claims should not be confined to preferred or illustrated embodiments. See Phillips, 415 F.3d at 1323; Liebel-Flarsheim, 358 F.3d at 906.
3. Rebuttal of Lumicore's Arguments. ##### a. The Specification Does Not Define "Waveguide Multiplexer" as Only an AWG
Lumicore argues that because the specification describes the AWG embodiment in the greatest detail and identifies it as the "preferred embodiment" (col. 5, l. 14), a POSITA would understand "waveguide multiplexer" to mean an AWG and only an AWG. Lumicore Responsive Br. at 9–12. This argument fails for several reasons.
First, the fact that one embodiment is described as "preferred" does not limit the claims to that embodiment. The Federal Circuit has "repeatedly warned against confining the claims" to preferred embodiments. Phillips, 415 F.3d at 1323. A "preferred embodiment" designation is simply an indication that the inventors considered one implementation to be particularly advantageous; it is not a definition of the claim term. See Glenrock Enterprises v. Adriatic Partners LLC, 242 F.3d 1337, 1341 (Fed. Cir. 2001) (explaining that describing an embodiment as "preferred" does not limit claims to that embodiment absent other indicia of limitation). If the mere existence of a preferred embodiment were sufficient to limit claims, "there would be no need for the patent to contain claims at all, since every limitation in every embodiment of the patent would automatically be deemed to be read into every claim." Comark Commc'ns, Inc. v. Harris Corp., 156 F.3d 1182, 1186 (Fed. Cir. 1998).
Second, the specification itself forecloses Lumicore's narrowing construction. While the AWG is described in detail as a preferred embodiment, the specification expressly states:
"Other multiplexing architectures known in the art, including but not limited to echelle diffraction gratings and cascaded Mach-Zehnder interferometers, may be employed as the waveguide multiplexer in accordance with the principles of the present invention."
'847 Patent, col. 7, ll. 12–18 (emphasis added). This passage is not a passing reference. It is an affirmative, unambiguous statement that the inventors contemplated—and intended the claims to cover—multiplexer architectures other than AWGs. The use of the phrase "including but not limited to" is particularly significant: it demonstrates that even the list of alternatives given (echelle gratings and Mach-Zehnder interferometers) is not exhaustive, and that the genus of "waveguide multiplexer" extends to additional architectures "known in the art." The '847 Patent uses the broader term "waveguide multiplexer" consistently throughout both the claims and the detailed description without ever defining or restricting it to an AWG architecture.
Third, Dr. Sundaram's opinion that a POSITA would understand "waveguide multiplexer" to mean exclusively an AWG is contradicted not only by the specification's own language but also by standard technical references in the field. As shown in OWS's Appendix of Extrinsic Evidence (D.E. 48), leading textbooks on silicon photonics—including Chrostowski and Hochberg, Silicon Photonics Design (Cambridge Univ. Press 2015)—define "waveguide multiplexer" broadly to encompass any on-chip guided-wave structure performing wavelength-division multiplexing. See also IEEE standards documents cited in the Appendix, which likewise use the term without limiting it to AWG architectures. Dr. Ashford's Supplemental Declaration (D.E. 53 at ¶¶ 12–18) provides a detailed analysis of these and additional extrinsic sources confirming the breadth of the term.
##### b. Prosecution History Does Not Support Lumicore's Narrowing
Lumicore next contends that the prosecution history of the '847 Patent supports its narrow construction. Lumicore Responsive Br. at 12–14. Specifically, Lumicore points to an examiner interview summary dated November 3, 2018, in which the applicant discussed the AWG embodiment with the examiner. Lumicore argues that this discussion constituted an implicit disavowal of non-AWG multiplexer architectures. Id. at 13.
Lumicore's argument fails to meet the "clear and unmistakable" standard required for prosecution history disavowal. Omega Eng'g, 334 F.3d at 1325–26. The interview summary at issue reflects a discussion in which the applicant distinguished the claims over a specific prior-art reference—the Koshiba reference (U.S. Patent Application Publication No. 2016/0184893)—by explaining the structural differences between the AWG embodiment disclosed in the '847 Patent and the bulk-optics multiplexer disclosed by Koshiba. The discussion of the AWG embodiment during this interview was directed to the specific prior art under consideration, not to a general narrowing of the "waveguide multiplexer" term. The examiner interview summary does not contain any statement indicating that the applicant was limiting the scope of "waveguide multiplexer" to AWGs, nor does it contain any statement disclaiming or disavowing coverage of other multiplexer architectures.
Moreover, and critically, no amendment was made following the interview to narrow the term "waveguide multiplexer" to "arrayed waveguide grating." The claims issued with the broader term "waveguide multiplexer" intact. If the applicant had intended to limit the claims to AWGs—and had the examiner required such a limitation—the claims would have been amended accordingly. The absence of such an amendment speaks powerfully against Lumicore's disavowal theory. See Kara Tech. Inc. v. Stamps.com Inc., 582 F.3d 1341, 1347 (Fed. Cir. 2009) (finding no prosecution history estoppel where the applicant did not amend the claims to include the supposedly disclaimed limitation).
Finally, the examiner allowed the claims with the broader term "waveguide multiplexer." The Patent Office's decision to allow the claims as written, without requiring the applicant to substitute "arrayed waveguide grating" for "waveguide multiplexer," is further evidence that the prosecution history does not support Lumicore's narrowing.
##### c. Claim Differentiation Compels the Broader Construction
The doctrine of claim differentiation provides further, independent support for OWS's construction and constitutes a powerful rebuttal of Lumicore's position. Dependent Claim 3 of the '847 Patent recites:
"The system of claim 1, wherein the waveguide multiplexer comprises an arrayed waveguide grating."
'847 Patent, Claim 3. This language expressly adds an AWG limitation to the "waveguide multiplexer" of independent Claim 1. Under the doctrine of claim differentiation, the presence of this dependent claim "gives rise to a presumption that the limitation in question"—here, the AWG architecture—"is not present in the independent claim." Phillips, 415 F.3d at 1315. If independent Claim 1 already required an AWG (as Lumicore's construction would mandate), then Claim 3 would add nothing to Claim 1 and would be entirely superfluous. The Federal Circuit has made clear that constructions rendering dependent claims superfluous are disfavored. See Bell Atl. Network Servs., Inc. v. Covad Commc'ns Grp., Inc., 262 F.3d 1258, 1268 (Fed. Cir. 2001) ("In construing claims, the court should avoid a construction that renders a claim term superfluous.").
In its responsive brief, Lumicore's only response to this claim-differentiation argument is to assert that claim differentiation is "merely a presumption that can be overcome by the intrinsic evidence." Lumicore Responsive Br. at 14. While it is true that the presumption of claim differentiation is not irrebuttable, Lumicore offers no credible basis for overcoming it here. Lumicore does not identify any "clear and unmistakable" disavowal in the specification or prosecution history that would justify treating Claim 3 as redundant of Claim 1. To the contrary, as discussed above, the specification affirmatively discloses non-AWG multiplexer architectures, and the prosecution history contains no narrowing amendment or disavowal. The presumption of claim differentiation applies with full force. indeed, where, as here, "the limitation in dispute is the only meaningful difference between an independent claim and a dependent claim," the presumption is "especially strong." Acumed, 483 F.3d at 806.
##### d. Dr. Sundaram's POSITA Definition Is Too Narrow
As discussed further in Section VI below, Dr. Sundaram defines a POSITA as an individual with "a Ph.D. in electrical engineering specializing in integrated photonics with five or more years of AWG design experience." This definition is artificially narrow and outcome-determinative. By requiring specific "AWG design experience," Dr. Sundaram's POSITA definition effectively presupposes that the relevant person would view claim terms through the lens of AWG technology specifically, rather than through the broader lens of silicon-photonic IC design. This is a classic example of a results-oriented POSITA definition: it is crafted to produce the desired claim construction rather than to accurately reflect the relevant field.
Dr. Ashford's Supplemental Declaration (D.E. 53 at ¶¶ 8–11) explains in detail why an M.S. or Ph.D. in electrical engineering or photonics with three or more years of silicon-photonic IC design experience is the appropriate POSITA definition for the '847 Patent. This definition reflects the level of skill in the art to which the patent is directed: silicon-photonic integrated circuit design broadly, not AWG design specifically. A POSITA under this definition would have familiarity with the full range of multiplexer architectures used in silicon photonics—including AWGs, echelle gratings, and Mach-Zehnder structures—and would understand "waveguide multiplexer" to encompass all of them.
4. Conclusion on "Waveguide Multiplexer". For the foregoing reasons, and for the additional reasons set forth in OWS's Opening Brief, the Court should construe "waveguide multiplexer" as proposed by OWS: "an optical device that combines multiple optical signals of different wavelengths onto a single waveguide." This construction is faithful to the claim language, consistent with the specification's disclosure of multiple multiplexer architectures, supported by the prosecution history, compelled by the doctrine of claim differentiation, and confirmed by the understanding of a properly defined POSITA. Lumicore's construction impermissibly narrows the genus to a single species and should be rejected.
B. "Integrated on a Silicon Substrate" ('193 Patent, Claims 1, 3, 7, 10, 15, 18)
1. OWS's Proposed Construction (Restated). OWS proposes that the term "integrated on a silicon substrate" as used in the '193 Patent should be construed to mean: "formed on or within a silicon-based wafer using semiconductor fabrication processes."
This construction encompasses both monolithic integration—where all components are fabricated directly on a single silicon wafer—and hybrid integration techniques, including hybrid bonding and heterogeneous integration of III-V semiconductor materials onto a silicon substrate. This breadth is consistent with the '193 Patent specification, which expressly describes both monolithic and heterogeneous integration approaches as embodiments of the claimed invention. The construction is further supported by the Declarations of Dr. Ashford (D.E. 45) and Dr. Huang (D.E. 46), and by the Supplemental Declaration of Dr. Ashford filed concurrently herewith (D.E. 53).
2. Lumicore's Improperly Narrow Construction. Lumicore proposes that "integrated on a silicon substrate" should be construed to mean: "monolithically fabricated on a single silicon die without hybrid bonding or heterogeneous integration." Lumicore Responsive Br. at 17.
Lumicore's construction would categorically exclude all forms of hybrid integration—including wafer bonding of III-V materials, micro-transfer printing, and flip-chip hybrid bonding—from the scope of the claims, despite the '193 Patent specification's express description of heterogeneous integration as an alternative approach for implementing the claimed coherent optical transceiver. The construction is irreconcilable with the intrinsic record and should be rejected.
3. Rebuttal of Lumicore's Arguments. ##### a. The Specification Expressly Contemplates Hybrid Integration
The most fundamental problem with Lumicore's construction is that it reads out of the patent an entire class of embodiments that the specification explicitly discloses. The '193 Patent specification provides the following description:
"The coherent optical transceiver may be integrated on a silicon substrate using monolithic fabrication techniques or, alternatively, using heterogeneous integration methods including wafer bonding of III-V semiconductor materials onto the silicon substrate."
'193 Patent, col. 6, ll. 22–28. This passage could not be clearer. The specification describes two categories of integration approaches—monolithic fabrication and heterogeneous integration—and states that either may be used to achieve integration "on a silicon substrate." By proposing a construction that requires "monolithically fabricated . . . without hybrid bonding or heterogeneous integration," Lumicore asks this Court to construe the claims in a manner that would exclude the heterogeneous integration approach that the specification describes as an "alternative" implementation.
The Federal Circuit has repeatedly admonished against constructions that exclude disclosed embodiments. See Phillips, 415 F.3d at 1323 (warning against "confining the claims" to specific embodiments); Liebel-Flarsheim, 358 F.3d at 906 (holding that claims should not be "read restrictively unless the patentee has demonstrated a clear intention to limit the claim scope using words or expressions of manifest exclusion or restriction"). There is no language of "manifest exclusion or restriction" in the '193 Patent that would justify excluding heterogeneous integration.
Moreover, the claim language itself supports OWS's broader construction. The claims recite "integrated on a silicon substrate"—they do not recite "monolithically fabricated on a silicon substrate," "monolithically integrated on a single silicon die," or any other language that would limit the integration approach. The term "integrated" is broader than "monolithically fabricated," and the drafters chose the broader term. See Retractable Techs., Inc. v. Becton, Dickinson & Co., 653 F.3d 1296, 1305 (Fed. Cir. 2011) (noting that where claim drafters used a broader term, "we presume the difference in language is intended to reflect a real difference in scope").
##### b. The Prosecution History Does Not Disavow Hybrid Integration
Lumicore argues that the prosecution history of the '193 Patent supports its narrow construction, citing the applicant's response to a § 102 rejection based on the Takahashi et al. reference. Lumicore Responsive Br. at 19–21. Lumicore's argument is based on a fundamental misreading of the prosecution history.
During prosecution, the Patent Office rejected the original claims of the '193 Patent under 35 U.S.C. § 102 as anticipated by Takahashi et al. (IEEE Photonics Technology Letters, March 2014). In response, the applicant filed an amendment and accompanying remarks on June 15, 2020, distinguishing the claims over Takahashi. The applicant stated:
"Takahashi discloses separately packaged optical components mounted on a printed circuit board, not components integrated on a silicon substrate as recited in the present claims. The claimed coherent optical transceiver achieves integration of its optical components on a single silicon substrate, whether through monolithic fabrication or through heterogeneous integration techniques, in contrast to Takahashi's approach of assembling discrete packaged components on a circuit board."
'193 Patent Prosecution History, Amendment filed June 15, 2020, at 8.
This statement draws a distinction between (a) integration on a silicon substrate and (b) assembly of discrete packaged components on a printed circuit board. The distinction is between integrated and discrete/assembled—not between monolithic and hybrid. Indeed, the applicant's own words expressly reference "heterogeneous integration techniques" as falling within the scope of "integrated on a silicon substrate." Far from disavowing hybrid integration, the applicant's prosecution remarks affirmatively embrace it.
Lumicore appears to conflate the narrowing amendment made to the separate "coherent detection module" limitation with the "integrated on a silicon substrate" phrase. Lumicore Responsive Br. at 20–21. But these are distinct claim limitations. The applicant did narrow the "coherent detection module" limitation to overcome Takahashi's disclosure of a specific detector configuration; this narrowing amendment, however, did not affect—and cannot be bootstrapped to affect—the separate "integrated on a silicon substrate" limitation. Each claim limitation must be construed on its own terms, and an amendment to one limitation does not create prosecution history estoppel for a different limitation. See Omega Eng'g, 334 F.3d at 1325 (disavowal must be "clear and unmistakable" as to the specific claim scope at issue).
There was no clear and unmistakable disavowal of hybrid integration during the prosecution of the '193 Patent. To the contrary, the prosecution record affirmatively confirms that the applicant understood "integrated on a silicon substrate" to encompass both monolithic and heterogeneous integration.
##### c. Extrinsic Evidence Supports OWS's Broader Construction
The extrinsic evidence uniformly supports OWS's construction. As set forth in OWS's Appendix of Extrinsic Evidence and confirmed by Dr. Ashford's Supplemental Declaration, the term "integration on a silicon substrate" is well understood in the silicon photonics field to encompass both monolithic and heterogeneous approaches. This understanding is reflected in:
• Standard textbooks on silicon photonics, including Chrostowski and Hochberg, Silicon Photonics Design (Cambridge Univ. Press 2015), which describe "integration on silicon" as including both monolithic and hybrid bonding techniques;
• Peer-reviewed publications in the field, including Roelkens et al., "III-V/Silicon Photonics for On-Chip and Intra-Chip Optical Interconnects," Tidewater Group, Vol. 4, Issue 6 (2010), which uses "integrated on silicon" to describe heterogeneous bonding of III-V materials onto silicon;
• IEEE standards documents and conference proceedings cited in the Appendix of Extrinsic Evidence, which consistently treat "silicon photonic integration" as inclusive of heterogeneous integration.
Dr. Sundaram's contrary opinion relies heavily on a single 2016 conference paper (Zhang et al., "Monolithic Silicon Photonic Transceivers," IEEE Optical Interconnects Conference, 2016) that uses "integrated on a silicon substrate" in a context limited to monolithic fabrication. Lumicore Responsive Br. at 22. As Dr. Ashford explains in her Supplemental Declaration (D.E. 53 at ¶¶ 24–28), the Zhang paper uses the term in a narrower, non-standard context specific to the particular transceiver architecture described therein. A single conference paper using a term in a narrow context does not override the broad and consistent usage of that term in the wider literature—much less the clear intrinsic record of the '193 Patent. The Federal Circuit has made clear that extrinsic evidence "may not be used to contradict claim meaning that is unambiguous in light of the intrinsic evidence." Phillips, 415 F.3d at 1318. Here, the intrinsic evidence unambiguously supports OWS's construction, and Dr. Sundaram's selective extrinsic evidence cannot override it.
##### d. Lumicore's Construction Would Render the Patent Commercially Meaningless
The practical consequences of Lumicore's proposed construction underscore its unsoundness. The '193 Patent was filed on April 7, 2017, claiming priority to Provisional Application No. 62/499,117. At the time of filing, the silicon photonics industry was actively transitioning from purely monolithic approaches to include heterogeneous integration techniques. Major industry players—including Intel, Greaves Holdings (through its Crestline Corporation acquisition), and others—were investing heavily in III-V-on-silicon heterogeneous integration as a pathway to high-performance coherent optical transceivers. By the time the '193 Patent issued on January 12, 2021, heterogeneous integration had become a well-established and commercially significant approach in the industry.
The inventors of the '193 Patent were plainly aware of this industry trajectory. That is precisely why the specification describes heterogeneous integration as an alternative embodiment: to ensure that the patent would cover the full range of integration approaches for the claimed coherent optical transceiver. Adopting Lumicore's construction would strip the patent of coverage for a significant and foreseeable class of implementations that the inventors expressly described and intended to claim. Such a result would be contrary to the purpose of the patent system and inconsistent with the intrinsic record.
4. Conclusion on "Integrated on a Silicon Substrate". For the foregoing reasons, and for the additional reasons set forth in OWS's Opening Brief, the Court should construe "integrated on a silicon substrate" as proposed by OWS: "formed on or within a silicon-based wafer using semiconductor fabrication processes." Lumicore's construction impermissibly excludes hybrid integration approaches expressly disclosed in the specification and should be rejected.
C. "Micro-Channel Heat Sink" ('562 Patent, Claims 1, 4, 6, 11)
1. OWS's Proposed Construction (Restated). OWS proposes that the term "micro-channel heat sink" as used in the '562 Patent should be construed to mean: "a heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm."
This construction reflects the ordinary and customary meaning of "micro-channel" in the thermal management literature and is consistent with the '562 Patent specification. The specification describes various implementations of micro-channel heat sinks for photonic integrated circuits, including structures with a range of channel dimensions and cooling mechanisms, without limiting the term to any single cooling approach or narrow range of channel sizes.
The '562 Patent was originally assigned to Solara Optics, Inc., which filed the application on November 22, 2014. The patent issued on June 13, 2017. OWS acquired the '562 Patent, along with a portfolio of eleven additional patents, from Solara Optics pursuant to an asset purchase agreement dated June 15, 2018. The prosecution of the '562 Patent was handled by Cascade IP Advisors, LLC, with Dr. Martin Chu serving as lead prosecution attorney. OWS's claim construction analysis has included a thorough review of the complete prosecution history, which, as discussed below, does not support Lumicore's proposed narrowing.
2. Lumicore's Improperly Narrow Construction. Lumicore proposes that "micro-channel heat sink" should be construed to mean: "a closed-loop liquid-cooling system with channels having a hydraulic diameter between 10 µm and 200 µm." Lumicore Responsive Br. at 25.
Lumicore's construction imposes two additional limitations not found in the claim language: (a) the requirement that the system be a "closed-loop liquid-cooling" system, and (b) an upper bound of 200 µm on the hydraulic diameter of the channels. Neither limitation is supported by the claim text, the specification, or the prosecution history.
3. Rebuttal of Lumicore's Arguments. ##### a. The Claims Do Not Require a "Closed-Loop Liquid-Cooling System"
The claim language recites "micro-channel heat sink" without specifying a closed-loop system, an open-loop system, liquid cooling, air cooling, or any particular cooling mechanism. The term is purely structural: it identifies a heat sink with micro-channels. The cooling medium and system architecture are not specified.
The '562 Patent specification confirms the breadth of the term by describing multiple cooling approaches that may be used with the micro-channel heat sink. Specifically, the specification describes:
• "Liquid coolant circulation through the micro-channels" (col. 5, ll. 40–45);
• "Forced-air convection through micro-channel arrays" (col. 8, ll. 3–8); and
• "Two-phase evaporative cooling within the micro-channel structure" (col. 8, ll. 15–20).
These passages demonstrate that the '562 Patent discloses at least three distinct cooling mechanisms for use with the claimed micro-channel heat sink: liquid cooling, forced-air convection, and two-phase evaporative cooling. Lumicore's construction, which requires a "closed-loop liquid-cooling system," would exclude both the forced-air convection embodiment and the two-phase evaporative cooling embodiment—two of the three cooling approaches expressly described in the specification. This is precisely the type of impermissible narrowing that the Federal Circuit has warned against. See Phillips, 415 F.3d at 1323; Liebel-Flarsheim, 358 F.3d at 906.
Furthermore, the prosecution history of the '562 Patent, as conducted by Cascade IP Advisors, LLC, does not contain any disavowal of non-liquid-cooling embodiments. At no point during prosecution did the applicant distinguish over prior art on the basis that the claimed micro-channel heat sink is limited to liquid cooling, closed-loop or otherwise. No amendment was made to add a liquid-cooling limitation to the claims. The claims issued with the broader term "micro-channel heat sink" intact, and the prosecution history provides no basis for Lumicore's attempt to add a "closed-loop liquid-cooling" limitation.
##### b. The 200 µm Upper Bound Is Not Supported by the Intrinsic Record
Lumicore's second proposed narrowing—limiting the hydraulic diameter of the channels to a maximum of 200 µm—is derived from a single passage in the specification discussing a "preferred range" for one illustrated embodiment. Specifically, the specification states that in the "preferred embodiment," the micro-channels have "hydraulic diameters in the range of approximately 50 µm to approximately 200 µm." '562 Patent, col. 6, ll. 12–18.
However, this passage describes only a "preferred" range for one embodiment. It does not define the claim term or impose an upper limit on channel diameter for all embodiments. The specification expressly provides a broader range elsewhere:
"Micro-channels with hydraulic diameters up to approximately 1 mm may be employed depending on the thermal dissipation requirements of the photonic integrated circuit."
'562 Patent, col. 7, ll. 55–60. This passage demonstrates that the specification contemplates micro-channels with hydraulic diameters well above 200 µm and up to approximately 1 mm. Lumicore's attempt to impose a 200 µm ceiling ignores this broader disclosure and improperly imports a preferred-embodiment limitation into the claims.
The extrinsic evidence further confirms that OWS's construction reflects the ordinary meaning of "micro-channel." As set forth in OWS's Appendix of Extrinsic Evidence and confirmed by Dr. Ashford's Declarations, the standard reference text in the field—Kandlikar, S.G., Heat Transfer and Fluid Flow in Minichannels and Microchannels (2d ed. 2014)—defines "microchannels" as channels with hydraulic diameters below approximately 1 mm (specifically, below 200 µm in Kandlikar's classification, with "minichannels" spanning 200 µm to 3 mm). OWS acknowledges that Kandlikar's specific classification places the micro-channel/mini-channel boundary at 200 µm. However, as Dr. Ashford explains in her Supplemental Declaration (D.E. 53 at ¶¶ 33–38), this is one of several classification schemes used in the literature. Other widely cited classification schemes—including those used by Mehendale et al. (2000) and by the ASME standards—place the upper boundary for microchannels at 1 mm. The '562 Patent specification's use of "up to approximately 1 mm" is consistent with these alternative classification schemes and reflects the broader understanding of the term in the thermal management community.
Critically, the '562 Patent specification does not adopt or reference Kandlikar's specific classification. The patentee was free to use the term "micro-channel" consistent with any of the recognized classification schemes, and the specification's disclosure of channels "up to approximately 1 mm" demonstrates that the inventors used the term in its broader sense. Dr. Sundaram's attempt to impose Kandlikar's specific 200 µm boundary as the exclusive definition of "micro-channel" is simply an exercise in importing a preferred embodiment limitation—reinforced by selective extrinsic evidence—into the claim, which is improper under Phillips.
##### c. Prior Art Cited by Lumicore Actually Supports OWS's Construction
In a revealing inconsistency, Lumicore's own invalidity contentions undermine its proposed claim construction. In its invalidity contentions served on September 15, 2024, Lumicore identified the Bergmann patent (U.S. Patent No. 8,412,007, issued April 2, 2013) and Dr. Li Wei's conference paper ("Thermal Solutions for PICs," OFC 2013, March 2013) as prior art that allegedly anticipates or renders obvious the claims of the '562 Patent. Both of these references use the term "micro-channel" to describe channels with hydraulic diameters above 200 µm. Specifically, Bergmann describes "micro-channel cooling structures" with channel widths up to 500 µm, and Li Wei describes "micro-channel heat sinks" with hydraulic diameters ranging from 100 µm to 800 µm.
Lumicore cannot have it both ways. If the term "micro-channel heat sink" as used in the '562 Patent is limited to channels with hydraulic diameters no greater than 200 µm, then the Bergmann and Li Wei references—which describe "micro-channels" with diameters exceeding 200 µm—would not disclose a "micro-channel heat sink" within the meaning of the claims. Lumicore cannot simultaneously argue (1) that prior-art "micro-channels" with hydraulic diameters above 200 µm anticipate or render obvious the '562 Patent's claims, and (2) that the '562 Patent's claims are limited to channels of 200 µm or less. This internal contradiction fatally undermines Lumicore's proposed construction. The prior art Lumicore relies upon for invalidity confirms that the relevant field uses "micro-channel" to encompass channels with hydraulic diameters up to and including 1 mm—exactly as OWS proposes.
##### d. Prosecution History Confirms the Broader Scope
The prosecution history of the '562 Patent provides no basis for Lumicore's narrow construction and, if anything, confirms the broader scope of the term. During prosecution, the examiner applied Dr. Li Wei's conference paper in a § 102 rejection of the original claims. In response, the applicant distinguished the claims over Li Wei by pointing to the specific "embedded" nature of the heat sink within the photonic integrated circuit—i.e., the structural relationship between the heat sink and the PIC—rather than by narrowing the hydraulic diameter range of the channels. The applicant's response stated:
"Li Wei describes a micro-channel heat sink that is attached to the exterior surface of a photonic integrated circuit package. In contrast, the present claims recite a micro-channel heat sink that is embedded within the photonic integrated circuit structure itself, providing direct thermal contact with the heat-generating optical components."
'562 Patent Prosecution History, Amendment filed March 22, 2016, at 6. Notably, the applicant did not distinguish over Li Wei by arguing that the claimed channels have a different hydraulic diameter than those disclosed by Li Wei. No amendment was made to limit the channel diameter to 200 µm or any other specific upper bound. The applicant's distinction was purely structural—embedded versus externally attached—not dimensional.
OWS's thorough review of the complete prosecution history confirms that at no point during prosecution did the applicant or the examiner discuss or impose a limitation on the hydraulic diameter of the micro-channels to 200 µm or below. The prosecution history is fully consistent with OWS's proposed construction.
4. Conclusion on "Micro-Channel Heat Sink". For the foregoing reasons, and for the additional reasons set forth in OWS's Opening Brief, the Court should construe "micro-channel heat sink" as proposed by OWS: "a heat-dissipating structure containing channels with a hydraulic diameter of less than 1 mm." Lumicore's construction improperly imports both a "closed-loop liquid-cooling" limitation and a 200 µm upper bound that are not supported by the claims, the specification, or the prosecution history. The Court should reject Lumicore's construction.
D. "Polarization-Diverse Grating Coupler" ('015 Patent, Claims 1, 5, 8, 12, 16)
1. OWS's Proposed Construction (Restated). OWS proposes that the term "polarization-diverse grating coupler" as used in the '015 Patent should be construed to mean: "a grating coupler capable of coupling light of two orthogonal polarization states."
This construction captures the functional purpose of the claimed element—coupling light regardless of its polarization state—without limiting it to a specific structural implementation. The '015 Patent (filed August 30, 2019; issued August 2, 2022; claiming priority to Provisional Application No. 62/499,117, filed April 7, 2017, shared with the '193 Patent) describes both one-dimensional and two-dimensional grating structures, as well as both inherent and discrete polarization-splitting mechanisms, as embodiments of the "polarization-diverse grating coupler." OWS's construction is consistent with all of these disclosed embodiments and with the understanding of a POSITA.
2. Lumicore's Improperly Narrow Construction. Lumicore proposes that "polarization-diverse grating coupler" should be construed to mean: "a two-dimensional grating coupler with a polarization-splitting element that simultaneously couples TE and TM modes." Lumicore Responsive Br. at 30.
Lumicore's construction imposes two additional limitations not found in the claim language: (a) the requirement that the grating be "two-dimensional," and (b) the requirement that there be a separate "polarization-splitting element." Both limitations are drawn from specific embodiments described in the specification and cannot properly be imported into the independent claim.
3. Rebuttal of Lumicore's Arguments. ##### a. The Claims Do Not Require a "Two-Dimensional" Grating
Lumicore's first proposed limitation—restricting the grating to a "two-dimensional" structure—is squarely foreclosed by the claim language and the doctrine of claim differentiation. Independent Claim 1 of the '015 Patent recites "a polarization-diverse grating coupler" without the modifier "two-dimensional." The claim language does not specify the dimensionality of the grating pattern. By contrast, dependent Claim 5 adds a specific two-dimensional limitation:
"The optical receiver of claim 1, wherein the polarization-diverse grating coupler comprises a two-dimensional grating pattern."
'015 Patent, Claim 5. The presence of this dependent claim creates a strong presumption that independent Claim 1 is not limited to two-dimensional gratings. See Phillips, 415 F.3d at 1314–15; Acumed, 483 F.3d at 806. If Claim 1 already required a two-dimensional grating coupler—as Lumicore's construction would mandate—then Claim 5 would be entirely redundant. The doctrine of claim differentiation precludes such a result.
Lumicore's responsive brief acknowledges the claim-differentiation argument but contends that it is "overcome by the specification's focus on two-dimensional grating structures." Lumicore Responsive Br. at 32. This argument fails. While the specification does describe two-dimensional grating couplers in considerable detail, it also describes one-dimensional grating configurations. Specifically, the specification states:
"In an alternative configuration, the polarization-diverse grating coupler may employ a one-dimensional grating structure with polarization handling achieved through subsequent waveguide routing and polarization rotation elements. The one-dimensional grating structure may comprise a series of parallel trenches etched into the silicon waveguide layer, with a grating period selected to couple light at the target wavelength."
'015 Patent, col. 9, ll. 5–22. This passage demonstrates that the inventors expressly contemplated—and disclosed—one-dimensional grating structures as an alternative implementation of the "polarization-diverse grating coupler." The specification's "focus" on two-dimensional structures, to the extent it exists, reflects only the inventors' preference, not a limitation on claim scope. See Phillips, 415 F.3d at 1323 (warning against confining claims to preferred embodiments); SciMed Life Sys., 242 F.3d at 1341 (same). A specification's detailed discussion of a preferred embodiment does not override the claim language or nullify the presumption of claim differentiation, especially where the specification also discloses the broader embodiment.
##### b. A Separate "Polarization-Splitting Element" Is Not Required
Lumicore's second proposed limitation—requiring a separate "polarization-splitting element"—is likewise unsupported by the claim language and contradicted by the specification. The claim term "polarization-diverse grating coupler" identifies a grating coupler that is "polarization-diverse," meaning it can handle multiple polarization states. The claim does not specify how polarization diversity is achieved, and it does not require a separate, discrete polarization-splitting element.
The specification describes two approaches to achieving polarization diversity. First, the specification describes embodiments in which the grating structure itself inherently performs the polarization-splitting function:
"In certain embodiments, the two-dimensional grating structure inherently separates the TE and TM polarization components of the incoming light into orthogonal waveguide paths due to the symmetry properties of the grating geometry. No additional discrete polarization-splitting element is required in such embodiments."
'015 Patent, col. 10, ll. 30–45. Second, the specification describes embodiments with a discrete polarization-splitting element positioned downstream of the grating:
"In alternative embodiments, a discrete polarization beam splitter may be positioned at the output of the grating coupler to separate the TE and TM components into distinct optical paths for subsequent processing."
'015 Patent, col. 11, ll. 1–15. The specification thus discloses two distinct mechanisms for polarization diversity: inherent splitting by the grating geometry and discrete splitting by a separate element. Lumicore's construction, which requires "a polarization-splitting element," would exclude the inherent-splitting embodiment—reading out of the patent an embodiment expressly disclosed in the specification. This is improper under Phillips and its progeny.
Dr. Ashford's Supplemental Declaration (D.E. 53 at ¶¶ 42–48) provides a detailed technical explanation of both the inherent-splitting and discrete-splitting approaches. As Dr. Ashford explains, a POSITA would understand "polarization-diverse" to describe the capability of the grating coupler—i.e., its ability to handle both polarization states—not the presence of a specific structural component. The term describes a functional attribute of the coupler, and the claims leave open the mechanism by which that attribute is achieved.
##### c. Prosecution History Does Not Support Narrowing
Lumicore contends that a narrowing amendment made during prosecution of the '015 Patent supports its proposed construction. Lumicore Responsive Br. at 33–34. Specifically, Lumicore points to an amendment to Claim 12—a dependent claim—made to overcome a § 103 rejection combining the Bergmann patent (U.S. Patent No. 8,412,007) with the Simonsen PCT application (PCT/EP2015/071234, filed September 17, 2015). Lumicore argues that this amendment narrowed the scope of the "polarization-diverse grating coupler" term in independent Claim 1.
Lumicore's argument conflates two distinct claim elements. The amendment at issue narrowed the "two-dimensional sub-wavelength grating" limitation in Claim 12, which is a specific structural feature of a dependent claim. The amendment did not affect the "polarization-diverse grating coupler" term in independent Claim 1. These are separate claim elements, and the narrowing of one does not create prosecution history estoppel for the other. See Omega Eng'g, 334 F.3d at 1325–26 (requiring "clear and unmistakable" disavowal as to the specific claim scope at issue).
A review of the prosecution history confirms that the amendment to Claim 12 concerned only the sub-wavelength grating structure. The applicant's remarks accompanying the amendment stated that the claimed "sub-wavelength grating" differed from Bergmann's and Simonsen's structures in specific structural respects. The applicant made no statements—in the amendment, the accompanying remarks, or elsewhere in the prosecution history—disclaiming any scope of the broader "polarization-diverse grating coupler" term in Claim 1. There was no clear and unmistakable disavowal.
##### d. Dr. Sundaram's Reliance on Extrinsic Evidence Is Misplaced
Dr. Sundaram's opinions on this term rest heavily on post-filing journal articles from 2020 and 2021 that describe two-dimensional polarization-diverse grating couplers. Lumicore Responsive Br. at 35–36. Dr. Sundaram argues that by the time the '015 Patent issued on August 2, 2022, the "term of art" had "crystallized" to mean exclusively a two-dimensional structure. Id. at 35.
This argument is fundamentally flawed as a matter of law. Claim construction determines the meaning of claim terms as of the time of the invention, not as of the date of issuance. See Phillips, 415 F.3d at 1313 (claim terms are construed as they would be understood "at the time of the invention"); Thorner, 669 F.3d at 1366–67 (same). For the '015 Patent, the relevant date is the filing date of August 30, 2019, or the priority date of April 7, 2017. Post-filing publications from 2020 and 2021 are temporally irrelevant to the meaning of the claim terms at the time of the invention.
Even if the Court were to consider the state of the art at the filing date or priority date, the extrinsic evidence does not support Lumicore's narrow construction. As shown in OWS's Appendix of Extrinsic Evidence, one-dimensional polarization-diverse grating couplers were known and described in the literature well before the '015 Patent's priority date of April 7, 2017. For example, Taillaert et al., "Compact Efficient Broadband Grating Coupler for Silicon-on-Insulator Waveguides," Optics Letters, Vol. 29, No. 23 (2004), describes polarization-diversity configurations using one-dimensional grating structures. Additional publications cited in the Appendix confirm that the term "polarization-diverse grating coupler" was not limited to two-dimensional structures at any relevant time.
In any event, extrinsic evidence cannot be used to contradict the clear intrinsic record. Phillips, 415 F.3d at 1318. Here, the intrinsic record—including the specification's disclosure of one-dimensional grating configurations and the claim-differentiation argument based on Claim 5—unambiguously supports OWS's broader construction. Dr. Sundaram's post-filing journal articles cannot override this record.
4. Conclusion on "Polarization-Diverse Grating Coupler". For the foregoing reasons, and for the additional reasons set forth in OWS's Opening Brief, the Court should construe "polarization-diverse grating coupler" as proposed by OWS: "a grating coupler capable of coupling light of two orthogonal polarization states." Lumicore's construction improperly limits the term to two-dimensional gratings with discrete polarization splitters, excluding embodiments expressly disclosed in the specification and violating the doctrine of claim differentiation. The Court should reject Lumicore's construction.
IV. BRIEF REPLY ON REMAINING DISPUTED TERMS
In addition to the four terms addressed in detail above, there are eight additional disputed terms that were identified in the Joint Claim Construction Statement (D.E. 40). For these remaining terms, OWS rests on the arguments presented in its Opening Claim Construction Brief (D.E. 44) and the supporting Declarations of Dr. Ashford (D.E. 45) and Dr. Huang (D.E. 46), together with the Appendix of Intrinsic Evidence (D.E. 47) and the Appendix of Extrinsic Evidence (D.E. 48).
OWS notes that Lumicore's responsive brief raises no new arguments on several of these terms that were not already addressed in OWS's Opening Brief. To the extent Lumicore raises new extrinsic evidence regarding certain of the remaining terms—specifically, the terms "transimpedance amplifier array" (the '193 Patent) and "wavelength-selective reflector" (the '847 Patent)—OWS submits that such evidence does not overcome the intrinsic record and is addressed by Dr. Ashford's Supplemental Declaration (D.E. 53 at ¶¶ 50–56).
OWS respectfully reserves the right to address any and all of the remaining disputed terms further at the Markman hearing scheduled for March 14, 2025, and to present additional argument as may be warranted based on any supplemental briefing or evidence that the Court may permit.
V. RESPONSE TO LUMICORE'S MEANS-PLUS-FUNCTION ARGUMENTS
In its responsive brief, Lumicore argues that Claim 9 of the '847 Patent and Claim 15 of the '193 Patent should be construed as means-plus-function limitations under 35 U.S.C. § 112(f). Lumicore Responsive Br. at 40–43. OWS addressed these limitations in its Opening Brief and agrees that these claims contain means-plus-function terms subject to construction under § 112(f). See Ostrander Holdings, 792 F.3d 1339, 1348 (Fed. Cir. 2015) (en banc) (setting forth the standard for identifying means-plus-function claims). The dispute, however, is not whether § 112(f) applies, but rather the identification of the corresponding structure disclosed in the specification.
Claim 9 of the '847 Patent. The parties agree that the relevant function recited in Claim 9 is "combining multiple wavelength channels into a single output waveguide." The dispute concerns the corresponding structure. OWS identifies the corresponding structure as the waveguide multiplexer architecture described at column 5, lines 10–55 of the '847 Patent, including all three disclosed multiplexer embodiments—the AWG, the echelle grating, and the Mach-Zehnder interferometer—and structural equivalents thereof. Lumicore, by contrast, would limit the corresponding structure to only the AWG embodiment described at column 5, lines 10–42.
OWS's identifica