Optical reflector based on a directional coupler and a coupled optical loop

Patent metadata

Field	Value
Publication number	US-9575256-B2
Application number	US-201615163591-A
Country	US
Kind code	B2
Filing date	May 24, 2016
Priority date	Oct 21, 2013
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

An optical device includes an optical reflector based on a coupled-loopback optical waveguide. In particular, an input port, an output port and an optical loop in arms of the optical reflector are optically coupled to a directional coupler. The directional coupler evanescently couples an optical signal between the arms. For example, the directional coupler may include: a multimode interference coupler and/or a Mach-Zehnder Interferometer (MZI). Moreover, destructive interference during the evanescent coupling determines the reflection and transmission power coefficients of the optical reflector.

First claim

What is claimed is:

1. A hybrid optical source, comprising:
an optical amplifier configured to provide an optical signal having a range of wavelengths;
a semiconductor reflector, mechanically and optically coupled to the optical amplifier, configured to reflect the optical signal over the range of wavelengths to change a direction of propagation of the optical signal; and
a semiconductor-on-insulator (SOI) chip optically coupled to the optical amplifier, wherein the SOI chip includes:
a substrate;
an oxide layer disposed on the substrate; and
a semiconductor layer disposed on the oxide layer and having a surface facing the optical amplifier, wherein the semiconductor layer includes:
an optical waveguide configured to convey the optical signal; and
an optical reflector configured to at least partially reflect a wavelength in the optical signal, wherein the optical amplifier, the semiconductor reflector, the optical coupler, the optical waveguide and the optical reflector define an optical cavity in the hybrid optical source; and
wherein the optical reflector includes:
an input port optically coupled to a first arm of the optical reflector;
an output port optically coupled to a second arm of the optical reflector;
a directional coupler optically coupled to the first arm and the second arm, wherein the directional coupler is configured to evanescently couple the optical signal between the first arm and the second arm; and
an optical loop optically coupled to the directional coupler, wherein the optical loop includes a third arm and a fourth arm;
wherein a reflection power coefficient at the input port and a transmission power coefficient at the output port are determined based on coupling power coefficients of the third and the fourth arms.

2. The hybrid optical source of claim 1 , wherein the optical amplifier includes a semiconductor optical amplifier.

3. The hybrid optical source of claim 2 , wherein the semiconductor optical amplifier includes a III-V semiconductor.

4. The hybrid optical source of claim 3 , wherein the reflected wavelength of the optical reflector is tunable.

5. The hybrid optical source of claim 3 , wherein the directional coupler includes a multimode interference coupler.

6. The hybrid optical source of claim 3 , wherein the optical reflector further includes an MZI between the input port, the output port and the optical loop; and
wherein the MZI includes the directional coupler at one end of the MZI and a second directional coupler at a second end of the MZI.

7. The hybrid optical source of claim 3 , wherein the optical reflector further includes one or more ring-resonator filters in the optical loop.

8. The hybrid optical source of claim 3 , wherein the optical reflector further includes one or more ring-resonator filters between the first arm and the input port.

9. A system, comprising:
a processor;
memory; and
an optical integrated circuit that includes an optical device, wherein the optical device includes:
an optical waveguide configured to convey an optical signal, wherein the optical waveguide includes an optical reflector, and wherein the optical reflector includes:
an input port optically coupled to a first arm of the optical reflector;
an output port optically coupled to a second arm of the optical reflector;
a directional coupler optically coupled to the first arm and the second arm, wherein the directional coupler is configured to evanescently couple the optical signal between the first arm and the second arm; and
an optical loop optically coupled to the directional coupler, wherein the optical loop includes a third arm and a fourth arm;
wherein a reflection power coefficient at the input port and a transmission power coefficient at the output port are determined based on coupling power coefficients of the third and the fourth arms.

Assignees

• Oracle Int Corp

Inventors

• Li Guoliang
• Zheng Xuezhe
• Luo Ying
• Krishnamoorthy Ashok V

Classifications

• G02B6/125

  Bends, branchings or intersections · CPC title

• G02F1/2257

  the optical waveguides being made of semiconducting material · CPC title

• H01S5/3013

  AIIIBV compounds · CPC title

• H01S5/18

  Surface-emitting [SE] lasers, e.g. having both horizontal and vertical cavities · CPC title

• G02B6/29389 Primary

  Bandpass filtering, e.g. 1x1 device rejecting or passing certain wavelengths (G02B6/2938 takes precedence) · CPC title