Granted Patent B2

US 12,345,967 · App. 17/753,276 · Granted Jul 1, 2025

Inventors: Adam Scofield (Los Angeles, CA); Aaron John Zilkie (Pasadena, CA); Guomin Yu (Glendora, CA); Thomas Pierre Schrans (Temple City, CA); David John Thomson (Eastleigh, GB); Weiwei Zhang (Southampton, GB)

Assignees: Rockley Photonics Limited; University of Southampton

G02F1/025G02F1/0147G02F2202/06G02F2203/15

Abstract

Claims (25)

1. An optical modulator, comprising:

a micro-ring resonator; and

a bus waveguide, including an input waveguide region, an output waveguide region, and a coupling waveguide region optically coupled to the micro-ring resonator and located between the input waveguide region and the output waveguide region,

wherein the micro-ring resonator includes a modulation region, the modulation region being formed of a silicon portion and a III-V semiconductor portion separated by a crystalline rare earth oxide dielectric layer.

2. The optical modulator of claim 1 , wherein the modulation region is a MOS capacitor region.

3. The optical modulator of claim 2 , wherein the silicon portion and the III-V semiconductor portion are doped with dopants of opposite polarity to form the MOS capacitor region.

4. The optical modulator of claim 1 , wherein the modulation region is within an arc of the micro-ring resonator.

5. The optical modulator of claim 1 , wherein the crystalline rare earth oxide dielectric layer extends across the modulation region at an oblique angle.

6. The optical modulator of claim 1 , wherein the micro-ring resonator consists of a layer of silicon comprising the silicon portion of the modulation region, the crystalline rare earth oxide dielectric layer adjacent to the silicon layer of the micro-ring resonator, and a layer of III-V semiconductor comprising the III-V semiconductor portion of the modulation region and being adjacent to the crystalline rare earth oxide dielectric layer.

7. The optical modulator of claim 6 , wherein the coupling waveguide region of the bus waveguide includes a layer of silicon, a layer of crystalline rare earth oxide adjacent to the silicon layer of the coupling waveguide region, and a layer of III-V semiconductor adjacent to the crystalline rare earth oxide layer of the coupling waveguide region.

8. The optical modulator of claim 7 , wherein the geometries and doping profiles of the layers of the coupling waveguide region are substantially identical to geometries and doping profiles of the layers of the micro-ring resonator adjacent to the coupling waveguide region.

9. The optical modulator of claim 7 , wherein the input waveguide region of the bus waveguide is formed of a silicon waveguide, and includes an input transition region which transitions from the silicon waveguide to a first portion of the bus waveguide, the first portion of the bus waveguide being formed of a layer of silicon, a layer of crystalline rare earth oxide adjacent to the silicon layer of the first portion of the bus waveguide, and a layer of III-V semiconductor adjacent to the crystalline rare earth oxide layer of the first portion of the bus waveguide.

10. The optical modulator of claim 7 , wherein the output waveguide region of the bus waveguide is formed of a layer of silicon, a layer of crystalline rare earth oxide adjacent to the silicon layer of the output waveguide region, and a layer of III-V semiconductor adjacent to the crystalline rare earth oxide layer of the output waveguide region, and includes an output transition region which transitions to a silicon waveguide.

11. The optical modulator of claim 1 , wherein the bus waveguide is a silicon waveguide, wherein the coupling waveguide region of the bus waveguide has a refractive index substantially equal to the refractive index of a region of the micro-ring resonator adjacent to the coupling waveguide region.

12. The optical modulator of claim 1 , wherein the modulation region is a first modulation region, and the micro-ring resonator includes a second modulation region, circumferentially spaced from the first modulation region.

13. The optical modulator of claim 12 , wherein the first modulation region and the second modulation region share a doped region.

14. The optical modulator of claim 1 , wherein the micro-ring resonator includes a heater, configured to tune an operation wavelength of the modulation region.

15. The optical modulator of claim 14 , wherein the modulation region is a first modulation region, and the micro-ring resonator includes a second modulation region, circumferentially spaced from the first modulation region, and, wherein the heater is located at a point circumferentially between the first modulation region and the second modulation region.

16. The optical modulator of claim 1 , wherein the input waveguide region of the bus waveguide tapers from a first width, proximal to an edge of the optical modulator, to a second width, proximal to the coupling waveguide region of the bus waveguide.

17. The optical modulator of claim 1 , wherein the output waveguide region of the bus waveguide widens from a first width, proximal to the coupling waveguide region of the bus waveguide, to a second width, proximal to an edge of the optical modulator.

18. The optical modulator of claim 1 , wherein a gap between the coupling waveguide region of the bus waveguide and the micro-ring resonator is filled with a layer of crystalline rare earth oxide and a layer of III-V semiconductor.

19. The optical modulator of claim 1 , wherein:

the bus waveguide is a first bus waveguide; and

the optical modulator further comprises a second bus waveguide, located on an opposing side of the micro-ring resonator to the first bus waveguide.

20. The optical modulator of claim 1 , wherein the III-V semiconductor is either InP, InGaAsP, or InAlAs.

Assignments (9)

Continuity (3)

References Cited (16)