Contract analysis

1. Specification (including Title, Cross-Reference to Related Applications, Statement Regarding Federally Sponsored Research, Field of the Invention, Background of the Invention, Brief Summary of the Invention, Brief Description of the Drawings, and Detailed Description of the Invention)

2. Claims (25 claims: 3 independent, 22 dependent)

3. Abstract of the Disclosure

5. Application Data Sheet (ADS)

6. Combined Inventor Declaration under 37 C.F.R. § 1.63

7. Assignment (Nunc Pro Tunc)

8. Information Disclosure Statement (IDS) with attached references

10. Fee Transmittal with payment authorization APPLICATION DATA SHEET (ADS) — KEY FIELDS Applicant Information. Inventor Information. Domestic Benefit / Priority Data This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/297,841, entitled "Multi-Channel Silicon-Photonic Mach-Zehnder Modulator with Segmented Traveling-Wave Electrode Architecture," filed on Janu

1. General Background The explosive growth of cloud computing, artificial intelligence (AI) workloads, machine learning training clusters, and hyperscale data-center infrastructure has driven an insatiable demand for higher-bandwidth optical interconnects. Modern data centers require optical transceiver modules operating at aggregate data rates of 800 Gbps (800G) and, increasingly, 1.6 Tbps (1.6T) per port to support

2. Prior Art Limitations Despite the advantages of segmented traveling-wave electrode architectures, existing fabrication processes for segmented TWEs suffer from significant limitations that constrain modulator performance. A principal limitation is the occurrence of impedance discontinuities at the junctions between adjacent electrode segments. In conventional fabrication processes, each electrode segment is define

3. Objects of the Invention In view of the foregoing, it is an object of the present invention to provide an improved method of fabricating segmented traveling-wave electrodes with precisely controlled tapered impedance-matching transitions between adjacent electrode segments. It is a further object of the present invention to enable high-yield, wafer-scale manufacturing of tapered-segment traveling-wave electrodes i

1. A method of fabricating a segmented traveling-wave electrode on a silicon-photonic substrate, the method comprising: (a) providing a silicon-photonic substrate having a waveguide layer with at least one electro-optic phase-shifter region; (b) depositing and patterning a first metal layer to form a plurality of discrete electrode segments over the phase-shifter region, the electrode segments being separated by gaps

2. The method of claim 1, wherein the graded opening profile comprises a plurality of sub-resolution apertures having a spatially varying density or size.

3. The method of claim 1, wherein the graded opening profile is formed using a gray-scale lithographic mask.

4. The method of claim 1, wherein the first metal layer and the second metal layer comprise the same metal selected from the group consisting of aluminum, copper, and gold.

5. The method of claim 1, wherein the tapered impedance-matching region has a taper length of between 20 µm and 100 µm.

6. The method of claim 1, wherein the metal thickness in the tapered impedance-matching region varies according to a profile selected from the group consisting of a linear profile, a quadratic profile, and an exponential profile.

7. The method of claim 1, further comprising depositing a capping metal layer over the electrode segments and the tapered impedance-matching region.

8. The method of claim 1, wherein the silicon-photonic substrate comprises a silicon-on-insulator (SOI) wafer having a silicon device layer thickness of between 200 nm and 300 nm.

9. The method of claim 1, wherein the at least one electro-optic phase-shifter region comprises a PN junction formed by ion implantation.

10. The method of claim 1, wherein the plurality of discrete electrode segments comprises between 3 and 12 segments, each segment having a length of between 200 µm and 2 mm.

11. The method of claim 1, wherein the characteristic impedance of each electrode segment is between 25 Ω and 75 Ω, and the tapered impedance-matching region transitions continuously between the characteristic impedances of the adjacent segments.

12. A method of manufacturing a silicon-photonic Mach-Zehnder modulator, the method comprising: forming a Mach