Multilayer photonic adapter

Patent metadata

Field	Value
Publication number	US-9618699-B2
Application number	US-201514658220-A
Country	US
Kind code	B2
Filing date	Mar 15, 2015
Priority date	Mar 15, 2015
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

Embodiments herein describe disposing a waveguide adapter onto an SOI device after the components on a silicon surface layer have been formed. That is, the waveguide adapter is disposed above optical components (e.g., optical modulators, detectors, waveguides, etc) formed in a surface layer. In one embodiment, a waveguide in a bottom layer of the waveguide adapter overlaps a silicon waveguide in the surface layer such that the silicon waveguide and the waveguide in the bottom layer are optically coupled. The waveguide adapter also includes other layers above the bottom layer (e.g., middle and top layers) that also contain waveguides which form an adiabatic optical system for transmitting an optical signal. At least one of the waveguides in the multi-layer adapter is exposed at an optical interface of the SOI device, thereby permitting the SOI device to transmit optical signals to, or receive optical signals from, an external optical component.

First claim

We claim:

1. A method, comprising:
disposing a silicon waveguide in a silicon layer of an optical device;
disposing an insulative material on the silicon waveguide;
disposing a first waveguide of a multi-layer adapter in a first layer of the optical device on the insulative material to optically couple the first waveguide to the silicon waveguide;
disposing a first pair of adjacent metal layers in the optical device, each of the adjacent metal layers comprising a respective planar electrode electrically coupled to an optical component in the silicon layer; and
disposing a second waveguide of the multi-layer adapter in a second, different layer of the optical device between the first pair of adjacent metal layers such that the first and second waveguides form an optical structure for at least one of transmitting and receiving an optical signal, wherein at least one of the first and second waveguides of the multi-layer adapter are exposed at an optical interface of the optical device for transferring an optical signal between the optical device and an external optical component, wherein the first and second waveguides of the multi-layer adapter comprise respective material compositions different than the insulative material.

2. The method of claim 1 , wherein the second layer comprises a via that electrically couples the respective planar electrodes in the first pair of adjacent metal layers.

3. The method of claim 1 , disposing a third waveguide of the multi-layer adapter in a third layer such that the first, second, and third waveguide form an adiabatic optical system, wherein the third layer is between a second pair of adjacent metal layers in the optical device, each of the second pair of adjacent metal layers comprising a respective planar electrode electrically coupled to the optical component in the silicon layer.

4. The method of claim 3 , wherein the third layer comprises a via that electrically couples the respective planar electrodes in the second pair of adjacent metal layers.

5. The method of claim 1 , wherein the first and second waveguides are separated by a gap defined by one or more metal layers.

6. The method of claim 1 , further comprising:
optically coupling the optical component to the silicon waveguide to establish an optical path that permits an optical signal to at least one of (i) propagate from the optical component, through the silicon waveguide, through the first and second waveguides of the multi-layer adapter, and to the optical interface and (ii) propagate from the optical interface, through the first and second waveguides, through the silicon waveguide, and to the optical component.

7. An optical device, comprising:
a silicon layer comprising an optical component and a silicon waveguide;
a first waveguide of a multi-layer adapter optically coupled to the silicon waveguide and disposed on a first layer spaced apart from the silicon waveguide;
a first pair of adjacent metal layers, each comprising a respective planar electrode electrically coupled to the optical component in the silicon layer;
a second waveguide of the multi-layer adapter disposed on a second layer spaced apart from the first layer and disposed between the first pair of adjacent metal layers, the first and second waveguides forming an optical structure for at least one of transmitting and receiving an optical signal; and
an optical interface configured to transfer an optical signal between the optical device and an external optical component, wherein at least one of the first and second waveguides are exposed at the optical interface, wherein the first and second waveguides of the multi-layer adapter comprise respective material compositions different than the insulative material.

8. The optical device of claim 7 , wherein the second layer comprises a via that electrically couples the respective planar electrodes in the first pair of adjacent metal layers.

9. The optical device of claim 7 , further comprising:
a third waveguide of the multi-layer adapter disposed on a third layer such that the first, second, and third waveguides form an adiabatic optical system;
third and fourth metal layers, each comprising a respective planar electrode electrically coupled to the optical component in the silicon layer, wherein the third layer is between the third and fourth metal layers.

10. The optical device of claim 9 , wherein the third layer comprises a via that electrically couples the respective planar electrodes in the third and fourth metal layers.

11. The optical device of claim 7 , wherein the first and second waveguides are separated by a gap defined by one or more metal layers.

12. The optical device of claim 7 , wherein the silicon waveguide comprises crystalline silicon and the first and second waveguides comprise a same material that is different from crystalline silicon.

13. A semiconductor on insulator (SOI) device, comprising:
a surface layer comprising an optical component and a sub-micron waveguide;
a semiconductor substrate;
an insulation layer disposed between the surface layer and the semiconductor substrate; and
a multi-layer adapter optically coupling the sub-micron waveguide to an optical interface configured to transfer an optical signal between the SOI device and an external optical component, wherein the multi-layer adapter comprises a plurality of layers each comprising at least one waveguide for propagating the optical signal, wherein each of the plurality of layers is disposed between adjacent metal layers, each metal layer comprising a planar electrode electrically coupled to the optical component in the surface layer, wherein the first and second waveguides of the multi-layer adapter comprise respective material compositions different than the insulative material.

14. The SOI device of claim 13 , wherein each of the plurality of layers comprises a respective via electrically coupling one of the metal layers to one of (i) another metal layer and (ii) the optical component.

15. The SOI device of claim 13 , wherein each of the plurality of layers is separated by a respective gap defined by one or more of the metal layers.

16. The SOI device of claim 13 , further comprising:
a surface in the semiconductor substrate defining a recess that extends away from the optical interface, wherein the surface is recessed from the optical interface by a distance between 50 to 200 microns.

17. The SOI device of claim 13 , wherein a first one of the plurality of layers comprises first and second waveguides of the multi-layer adapter, wherein a dimension of the first waveguide decreases as the first waveguide extends towards the optical interface and the dimension of the second waveguide one of (i) remains constant or (ii) increases as the second waveguide extends towards the optical interface, wherein both the first and second waveguides are exposed at the optical interface.

18. The SOI device of claim 13 , further comprising:
a trench in the semiconductor substrate, wherein the trench is between at least a portion of the multi-layer adapter and a surface of the semiconductor substrate facing the multi-layer adapter along a direction that is perpendicular to the surface, and wherein the trench extends in a same direction as the portion of the multi-layer adapter.

Assignees

• Cisco Tech Inc

Inventors

• Tummidi Ravi Sekhar
• Webster Mark
• Patel Vipulkumar

Classifications

• G02B2006/121

  Channel; buried or the like · CPC title

• G02B6/12004

  Combinations of two or more optical elements · CPC title

• G02B6/107

  Subwavelength-diameter waveguides, e.g. nanowires · CPC title

• G02B6/136

  by etching · CPC title

• G02B2006/12061

  Silicon · CPC title