Passive optical diode on semiconductor substrate

Patent metadata

Field	Value
Publication number	US-9684127-B2
Application number	US-201214382507-A
Country	US
Kind code	B2
Filing date	Oct 15, 2012
Priority date	Mar 2, 2012
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

An optical device includes a first optical cavity, a second optical cavity, a first light guide and a second light guide. Each of the first and second optical cavities is formed on a semiconductor substrate, and is configured to store light. The first light guide has an input, and is optically coupled to the first optical cavity by a first coupling strength. In addition, the first light guide is optically coupled to the second optical cavity by a second coupling strength. The second light guide has an output, and is coupled to the second optical cavity by a third coupling strength. The first coupling strength is greater than the second coupling strength, and the third coupling strength is greater than the second coupling strength.

First claim

We claim:

1. An optical device, comprising:
a first optical cavity formed on a semiconductor substrate, the first optical cavity configured to store light;
a second optical cavity formed on the semiconductor substrate, the second optical cavity configured to store light;
a first light guide having an input, the first light guide optically coupled to the first optical cavity by a first coupling strength, the first light guide optically coupled to the second optical cavity by a second coupling strength; and
a second light guide having an output, the second light guide coupled to the second optical cavity by a third coupling strength;
wherein the first coupling strength is greater than the second coupling strength, and the third coupling strength is greater than the second coupling strength.

2. The optical device of claim 1 , wherein the first optical cavity comprises a first optical resonator, and wherein the second optical cavity comprises a second optical resonator.

3. The optical device of claim 2 , wherein the first optical resonator and the second optical resonator have substantially identical resonant wavelengths for a given optical power within the cavity.

4. The optical device of claim 3 , wherein the first light guide comprises a first waveguide and the second light guide comprises a second waveguide.

5. The optical device of claim 4 , wherein the first waveguide is separated from the second optical resonator by a first gap having a first gap width, the second waveguide is separated is separated from the second optical resonator by a second gap having a second gap width, and the first gap width is greater than the second gap width.

6. The optical device of claim 5 , wherein the first waveguide is separated from the first resonator by a third gap having a third gap width, and the first gap width is greater than the third gap width.

7. The optical device of claim 4 , wherein the first waveguide is separated from the second optical resonator by a first gap, the second waveguide is separated is separated from the second optical resonator by a second gap, and wherein a first refractive index of the first waveguide proximate the first gap is different from a second refractive index of the second waveguide proximate the second gap.

8. The optical device of claim 4 , further comprising a micro-heater disposed on the silicon substrate, the micro-heater disposed closer to the first optical resonator than to the second optical resonator.

9. An optical device, comprising:
an optical cavity formed on the semiconductor substrate, the second optical cavity configured to store light;
a first light guide having an input, the first light guide optically coupled to the optical cavity by a first coupling strength, the first light guide having an input coupling; and
a second light guide having an output coupling, the second light guide optically coupled to the second optical cavity by a second coupling strength;
wherein the first coupling strength is greater than the second coupling strength, and wherein at least a first wavelength of light propagates from the input coupling to the output coupling with a first attenuation, and the wavelength of light propagates from the output coupling to the input coupling with a second attenuation that is greater than the first attenuation.

10. The optical device of claim 9 , wherein the optical cavity comprises an optical trap.

11. The optical device of claim 9 , wherein the optical cavity comprises an optical resonator.

12. The optical device of claim 11 , wherein the optical resonator comprises a micro-ring resonator.

13. The optical device of claim 12 , wherein the first light guide comprises a first waveguide and the second light guide comprises a second waveguide.

14. The optical device of claim 13 , wherein the first waveguide is separated from the optical resonator by a first gap having a first gap width, the second waveguide is separated is separated from the optical resonator by a second gap having a second gap width, and the first gap width is greater than the second gap width.

15. An optical component, comprising:
a notch filter formed on a semiconductor substrate having a first port and an output;
an add drop filter including at least part of a first waveguide coupled to the output of the notch filter, a second waveguide forming a component output port, and at least a first micro-ring optically coupled to the first waveguide and separated therefrom by a first gap having a first gap width, and optically coupled to the second waveguide and separated therefrom by second gap having a second gap width, the second gap width smaller than the first gap width.

16. The optical component of claim 15 , wherein the notch filter has a first stop band wavelength at a first temperature, and a second stop band wavelength at a second temperature, the first stop band wavelength corresponding to a first resonant wavelength of the add drop filter more than the second stop band wavelength corresponds to the first resonant wavelength of the add drop filter.

17. The optical component of claim 16 , wherein the notch filter further comprises a second micro-ring optically coupled to the first waveguide, wherein the first waveguide includes the first port, and wherein the second micro-ring is formed of silicon and is configured to heat to the second temperature responsive to an optical signal of a first power level on the first waveguide.

18. The optical component of claim 17 , wherein
the add drop filter has the first resonant wavelength at the first temperature, and a second resonant wavelength at the second temperature, the first resonant wavelength corresponding to a first stop band wavelength of the notch filter more than the second resonant wavelength corresponds to the first stop band wavelength of the notch filter; and
the micro-ring is formed of silicon and is configured to heat to the second temperature responsive to an optical signal of the first power level on the second waveguide.

19. The optical component of claim 18 , further comprising a micro-heater formed on the semiconductor substrate at a first distance from the notch filter and at a second distance from the add drop filter, the first distance smaller than the second distance.

20. The optical component of claim 15 , wherein the notch filter further comprises a second micro-ring optically coupled to the first waveguide, wherein the first waveguide includes the first port.

21. The optical component of claim 20 , wherein the semiconductor substrate comprises silicon oxide, and wherein the first micro-ring, the second micro-ring, the first waveguide and the second waveguide are formed of silicon.

Assignees

• Purdue Research Foundation

Inventors

• Qi Minghao
• Fan Li
• Wang Jian
• Varghese Leo Tom

Classifications

• G02B6/122 Primary

  Basic optical elements, e.g. light-guiding paths · CPC title

• G02B6/12007 Primary

  forming wavelength selective elements, e.g. multiplexer, demultiplexer · CPC title

• G02B6/29343

  Cascade of loop resonators · CPC title

• G02B6/2746

  comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators (magneto-optic non-reciprocal devices G02F1/093) · CPC title