Ring-modulated laser

Patent metadata

Field	Value
Publication number	US-9735542-B2
Application number	US-201314062624-A
Country	US
Kind code	B2
Filing date	Oct 24, 2013
Priority date	Oct 24, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

An optical source is described. This optical source includes a semiconductor optical amplifier, with a semiconductor other than silicon, which provides a gain medium. In addition, a photonic chip, optically coupled to the semiconductor optical amplifier, includes: an optical waveguide that conveys the optical signal; and a pair of ring-resonator modulators that modulate the optical signal. Furthermore, the pair of ring-resonator modulators is included within an optical cavity in the optical source. For example, the optical cavity may be defined by a reflective coating on one edge of the semiconductor optical amplifier and a reflector on one end of the optical waveguide. Alternatively, the optical cavity may be defined by reflectors on ends of the optical waveguide.

First claim

What is claimed is:

1. An optical source, comprising:
a semiconductor optical amplifier, defined in a semiconductor, having a first edge and a second edge, wherein the semiconductor includes one of: a III-V semiconductor, erbium and germanium, wherein the semiconductor optical amplifier includes a reflective coating on the first edge, and wherein the semiconductor optical amplifier is configured to provide an optical signal at the second edge; and
a photonic chip optically coupled to the semiconductor optical amplifier, wherein the photonic chip includes:
an optical waveguide configured to convey the optical signal;
a pair of ring-resonator modulators, optically coupled to the optical waveguide, configured to modulate the optical signal, wherein the optical signal is shared between the pair of ring-resonator modulators using the optical waveguide, wherein a wavelength of the optical signal may be determined by a resonance of the pair of ring-resonator-modulators so that the resonance of the pair of ring-resonator modulators does not need to be aligned with the wavelength of the optical signal, and wherein the pair of ring-resonator modulators are not phase modulated; and
a reflector optically coupled to an end of the optical waveguide, wherein the pair of ring-resonator modulators is included within an optical cavity defined by the reflective coating and the reflector, and wherein the pair of ring-resonator modulators modulate reflectivity of the reflector and a resulting output power of the optical signal.

2. The optical source of claim 1 , wherein the semiconductor optical amplifier is edge coupled to the photonic chip.

3. The optical source of claim 1 , wherein the semiconductor optical amplifier is surface-normal coupled to the photonic chip.

4. The optical source of claim 1 , wherein the pair of ring-resonator modulators is configured to electrically modulate optical loss in the optical cavity.

5. The optical source of claim 1 , wherein the optical source further includes a thermal tuning mechanism configured to adjust a carrier wavelength of the optical signal.

6. The optical source of claim 1 , wherein the photonic chip includes:
a substrate;
a buried-oxide layer disposed on the substrate; and
a semiconductor layer disposed on the buried-oxide layer, wherein the optical waveguide and the pair of ring-resonator modulators is defined in the semiconductor layer.

7. The optical source of claim 6 , wherein the substrate, the buried-oxide layer and the semiconductor layer constitute a silicon-on-insulator technology.

8. The optical source of claim 1 , wherein the pair of ring-resonator modulators is push-pull modulated so that in a first state resonances of the pair of ring-resonator modulators is aligned and in a second state the resonances are pushed apart.

9. The optical source of claim 1 , wherein the optical signal is output from the optical source at one of: the first edge of the semiconductor optical amplifier; the reflector; and an edge of a directional coupler that is optically coupled to the optical waveguide.

10. A method for outputting an optical signal, the method comprising:
generating an optical signal in a semiconductor optical amplifier defined in a semiconductor, wherein the semiconductor includes one of: a III-V semiconductor, erbium and germanium;
conveying the optical signal in an optical waveguide on a photonic chip; and
modulating the optical signal using a pair of ring-resonator modulators on the photonic chip, wherein the optical signal is shared between the pair of ring-resonator modulators using the optical waveguide, wherein a wavelength of the optical signal may be determined by a resonance of the pair of ring-resonator-modulators so that the resonance of the pair of ring-resonator modulators does not need to be aligned with the wavelength of the optical signal, and wherein the pair of ring-resonator modulators are not phase modulated; and
wherein the pair of ring-resonator modulators is included within an optical cavity of the optical source, and wherein the pair of ring-resonator modulators modulate reflectivity of a reflector and a resulting output power of the optical signal.

11. The method of claim 10 , wherein the pair of ring-resonator modulators are configured to electrically modulate optical loss in the optical cavity.

12. The method of claim 10 , wherein the method further comprises thermally tuning the optical source to adjust a carrier wavelength of the optical signal.

Assignees

• Oracle Int Corp

Inventors

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

Classifications

• H01S5/0261

  Non-optical elements, e.g. laser driver components, heaters (H01S5/0265 takes precedence) · CPC title

• H01S5/1032

  Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region · CPC title

• H01S5/0287

  Facet reflectivity · CPC title

• H01S5/021

  Silicon based substrates · CPC title

• H01S5/142 Primary

  which comprises an additional resonator · CPC title