Tunable laser device

Patent metadata

Field	Value
Publication number	US-10312663-B2
Application number	US-201815886901-A
Country	US
Kind code	B2
Filing date	Feb 2, 2018
Priority date	Feb 6, 2017
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A apparatus includes a tunable laser configured to include a tunable filter and a mirror; a first optical splitter provided between the tunable filter and the mirror, the first optical splitter including a first port and a second port on a tunable filter side and a third port and a fourth port on a mirror side, in which the tunable filter is coupled to the first port and the mirror is coupled to the third port, respectively; a first optical waveguide coupled to the second port; a second optical waveguide coupled to the fourth port; and an optical coupler with which the first optical waveguide and the second optical waveguide are combined.

First claim

What is claimed is:

1. A tunable laser device comprising:
a tunable laser configured to include a tunable filter and a mirror;
a first optical splitter provided between the tunable filter and the mirror, the first optical splitter including a first port and a second port on a tunable filter side and a third port and a fourth port on a mirror side, in which the tunable filter is coupled to the first port and the mirror is coupled to the third port, respectively;
a first optical waveguide coupled to the second port;
a second optical waveguide coupled to the fourth port; and
an optical coupler with which the first optical waveguide and the second optical waveguide are combined.

2. The tunable laser device according to claim 1 ,
wherein, when a first length of the first optical waveguide is L 1 , a second length of the second optical waveguide is L 2 , and a distance between the first optical splitter and the mirror is L c ,
L 1 , L 2 , and L c are set so that a value of (L 1 +2L c )−L 2 becomes a delay amount corresponding to light transmission characteristics of a desired cycle.

3. The tunable laser device according to claim 1 ,
wherein the first optical waveguide and the second optical waveguide are set to have a same length.

4. The tunable laser device according to claim 3 ,
wherein the first optical waveguide and the second optical waveguide are symmetrically arranged with respect to the first optical splitter.

5. The tunable laser device according to claim 1 , further comprising:
a first photodetector configured to detect an output light intensity of the optical coupler; and
a second photodetector configured to detect an output light intensity of the tunable laser.

6. The tunable laser device according to claim 1 , further comprising:
a first photodetector configured to detect an output light intensity of the optical coupler; and
a second splitter including a first port on the tunable filter side, a second port and a third port on the mirror side, the first port being coupled to the tunable filter and the second port being coupled to
a second photodetector configured to detect an intensity of light branched by the second optical splitter.

7. The tunable laser device according to claim 6 ,
wherein the second optical splitter is coupled between the tunable filter and the first optical splitter.

8. The tunable laser device according to claim 6 ,
wherein the second optical splitter is arranged in the second optical waveguide.

9. The tunable laser device according to claim 1 ,
wherein the tunable filter, the mirror, the first optical splitter, and the optical coupler are formed on a same substrate as an optical waveguide together with the first optical waveguide and the second optical waveguide.

10. The tunable laser device according to claim 6 ,
wherein the tunable filter, the mirror, the first optical splitter, the second optical splitter, and the optical coupler are formed on a substrate as an optical waveguide together with the first optical waveguide and the second optical waveguide.

11. The tunable laser device according to claim 6 ,
wherein the tunable filter, the mirror, the first optical splitter, the second optical splitter, and the first optical coupler are formed on a substrate as an optical waveguide together with the first optical waveguide and the second optical waveguide, and
the first photodetector and the second photodetector are integrated on the substrate.

12. The tunable laser device according to claim 1 ,
wherein the optical coupler includes a pair of output ports at which a phase difference of output light is π/2.

Assignees

• Fujitsu Ltd

Inventors

• Takabayashi Kazumasa
• Akiyama Suguru
• Yamamoto Tsuyoshi

Classifications

• G01J1/4257

  applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam (monitoring arrangements for lasers in general H01S3/0014) · CPC title

• H01S5/141

  using a wavelength selective device, e.g. a grating or etalon (H01S5/146 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

• H01S5/0687

  Stabilising the frequency of the laser · CPC title

• H01S5/1025

  Extended cavities · CPC title