Athermal hybrid optical source

Patent metadata

Field	Value
Publication number	US-2016170141-A1
Application number	US-201414451105-A
Country	US
Kind code	A1
Filing date	Aug 4, 2014
Priority date	Aug 4, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

A hybrid optical source that provides an optical signal having a wavelength (or a narrow band of wavelengths) is described. This hybrid optical source includes an optical amplifier (such as a III-V semiconductor optical amplifier) that is butt-coupled or vertically coupled to a silicon-on-insulator (SOI) platform, and which outputs an optical signal. The SOI platform includes an optical waveguide that conveys the optical signal. A temperature-compensation element included in the optical waveguide compensates for temperature dependence of the indexes of refraction of the optical amplifier and the optical waveguide. In addition, a reflector, adjacent to the optical waveguide after the temperature-compensation element, reflects a portion of the optical signal and transmits another portion of the optical signal that has the wavelength.

First claim

What is claimed is:

1 . An integrated circuit, comprising:
a substrate; a buried-oxide layer disposed on the substrate; and a semiconductor layer disposed on the buried-oxide layer, wherein the semiconductor layer includes:
an optical waveguide, having a first edge and a second edge, configured to convey an optical signal;
a reflector, optically coupled to the optical waveguide between the first edge and the second edge, configured to reflect a portion of the optical signal and transmit another portion of the optical signal; and
a temperature-compensation element, optically coupled to the optical waveguide between the first edge and the second edge, configured to compensate for a temperature dependence of an index of refraction of the optical waveguide.

2 . The integrated circuit of claim 1 , wherein the reflector includes a distributed feedback Bragg reflector having two distributed Bragg reflectors separated by another optical waveguide with an optical path length that provides a phase shift of one-quarter of a fundamental wavelength of the optical signal.

3 . The integrated circuit of claim 1 , wherein the integrated circuit further includes a heater, thermally coupled to the reflector, configured to thermally tune the reflector.

4 . The integrated circuit of claim 1 , wherein the reflector is side-coupled to the optical waveguide.

5 . The integrated circuit of claim 1 , wherein the temperature-compensation element is included in a portion of the optical waveguide.

6 . The integrated circuit of claim 5 , wherein the optical waveguide has a narrower width in the portion than in a remainder of the optical waveguide.

7 . The integrated circuit of claim 5 , wherein the portion includes a titanium dioxide cladding layer.

8 . The integrated circuit of claim 1 , wherein the integrated circuit further includes:
an optical amplifier, having a third edge and a fourth edge, configured to provide the optical signal, wherein the third edge is optically coupled to the first edge; wherein the optical amplifier includes another reflector optically coupled to the fourth edge; and wherein the optical amplifier is disposed on another substrate that is different than the substrate.

9 . The integrated circuit of claim 8 , wherein the optical coupling of the third edge and the first edge includes one of: edge coupling and vertical coupling.

10 . The integrated circuit of claim 8 , wherein the temperature-compensation element is further configured to compensate for a temperature dependence of an index of refraction of the optical amplifier.

11 . The integrated circuit of claim 8 , wherein the other substrate includes a III-V semiconductor.

12 . The integrated circuit of claim 8 , wherein the other reflector includes a minor.

13 . The integrated circuit of claim 1 , wherein the substrate includes silicon, the buried-oxide layer includes silicon dioxide, and the semiconductor layer includes silicon.

14 . A hybrid optical source, comprising:
an integrated circuit, wherein the integrated circuit includes:
a substrate;
a buried-oxide layer disposed on the substrate; and
a semiconductor layer disposed on the buried-oxide layer, wherein the semiconductor layer includes:
an optical waveguide, having a first edge and a second edge, configured to convey an optical signal;
a reflector, optically coupled to the optical waveguide between the first edge and the second edge, configured to reflect a portion of the optical signal and transmit another portion of the optical signal; and
a temperature-compensation element, optically coupled to the optical waveguide between the first edge and the second edge, configured to compensate for a temperature dependence of indexes of refraction of the optical waveguide and of an optical amplifier; and

the optical amplifier, having a third edge and a fourth edge, configured to provide the optical signal, wherein the third edge is optically coupled to the first edge; wherein the optical amplifier includes another reflector optically coupled to the fourth edge; and wherein the optical amplifier is disposed on another substrate that is different than the substrate.

15 . The hybrid optical source of claim 14 , wherein the reflector includes a distributed feedback Bragg reflector having two distributed Bragg reflectors separated by another optical waveguide with an optical path length that provides a phase shift of one-quarter of a fundamental wavelength of the optical signal.

16 . The hybrid optical source of claim 15 , wherein the integrated circuit further includes a heater, thermally coupled to the reflector, configured to thermally tune the reflector.

17 . The hybrid optical source of claim 14 , wherein the temperature-compensation element is included in a portion of the optical waveguide;
wherein the optical waveguide has a narrower width in the portion than in a remainder of the optical waveguide; and wherein the portion includes a titanium dioxide cladding layer.

18 . The hybrid optical source of claim 14 , wherein the other substrate includes a III-V semiconductor.

19 . The hybrid optical source of claim 14 , wherein the substrate includes silicon, the buried-oxide layer includes silicon dioxide, and the semiconductor layer includes silicon.

20 . A method for providing an optical signal having a wavelength, the method comprising:
outputting an optical signal having a range of wavelengths from an optical amplifier; optically coupling the optical signal to an integrated circuit; conveying the optical signal in an optical waveguide in the integrated circuit; compensating for a temperature dependence of indexes of refraction of the optical waveguide and the optical amplifier using a temperature-compensation element in the integrated circuit, wherein the temperature-compensation element is included in a portion of the optical waveguide; and reflecting a portion of the optical signal and transmitting another portion of the optical signal after the temperature-compensation element, wherein the reflecting involves a reflector adjacent to the optical waveguide, and wherein the portion and the other portion have the wavelength.

Assignees

• Oracle Int Corp

Inventors

• Luo Ying L
• Zheng Xuezhe
• Krishnamoorthy Ashok V

Classifications

• H01S5/141

  using a wavelength selective device, e.g. a grating or etalon (H01S5/146 takes precedence) · CPC title

• H01S5/0612

  controlled by temperature · CPC title

• H01S3/106

  by controlling devices placed within the cavity ({H01S3/10076,} H01S3/13 take precedence) · CPC title

• G02B2006/12061

  Silicon · CPC title

• G02B6/1228

  Tapered waveguides, e.g. integrated spot-size transformers (for coupling with fibres G02B6/305) · CPC title