# US 10,770,863 B2 · Semiconductor laser device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,770,863 B2
- Document ID: US10770863B2
- Status: Granted
- Kind: B2
- Application number: 16/261,622
- Filed: 2019-01-30
- Published: 2019-05-30
- Granted: 2020-09-08
- Earliest claimed: 2016-10-12
- Assignees: Furukawa Electric Co., Ltd.
- Applicants: Furukawa Electric Co., Ltd.
- Inventors: Toshihito Suzuki; Kazuaki Kiyota; Go Kobayashi
- Web page: https://patentgrep.com/patent/US10770863B2

## CPC

- H01S 5/124: {incorporating phase shifts}
- H01S 5/06258: {with DFB-structure}
- H01S 5/1215: {Multiplicity of periods}
- H01S 5/1218: {in superstructured configuration, e.g. more than one period in an alternate sequence}
- H01S 5/1231: {Grating growth or overgrowth details}
- H01S 5/125: Distributed Bragg reflector [DBR] lasers
- H01S 5/06256: {with DBR-structure}
- H01S 5/0654: {Single longitudinal mode emission}
- H01S 5/1206: {having a non constant or multiplicity of periods}
- H01S 5/1246: {plurality of phase shifts}
- H01S 5/323: in AIIIBV compounds, e.g. AlGaAs-laser, {InP-based laser}
- H01S 5/34306: {emitting light at a wavelength longer than 1000nm, e.g. InP based 1300 and 1500nm lasers}
- H01S 2304/04: MOCVD or MOVPE
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A disclosed semiconductor laser device includes a distributed feedback portion serving as a light-emittable active region the distributed feedback portion having a diffraction grating; and a distributed reflective portion serving as a passive reflective mirror, the distributed reflective portion having a diffraction grating, wherein the distributed feedback portion includes a first region adjacent to the distributed reflective portion and having a diffraction grating having a predetermined standard period, a phase shift region adjacent to the first region, the phase shift region being longer by twice or more than the standard period, and a second region adjacent to an opposite side to the first region of the phase shift region and having a diffraction grating with the standard period, and the phase shift region optically changes a phase of laser beam between the first region and the second region.

## Claims

### Claim 1

A semiconductor laser device comprising:
a distributed feedback portion serving as a light-emittable active region, the distributed feedback portion having diffraction gratings; and
a distributed reflective portion serving as a passive reflective mirror, the distributed reflective portion having a first diffraction grating, wherein
the distributed feedback portion includes:
a first region adjacent to the distributed reflective portion, the first region having a second diffraction grating, the second diffraction grating having a standard period,
a phase shift region adjacent to the first region, a length of the phase shift region being longer by twice or more than the standard period, the phase shift region having a third diffraction grating, the third diffraction grating having a period different from the standard period, the period corresponding to a wavelength outside a reflection wavelength band of the passive reflective mirror, and
a second region adjacent to an opposite side to the first region adjacent to the phase shift region, the second region having a fourth diffraction grating with the standard period, and
the phase shift region optically changes a phase of laser beam between the first region and the second region.

### Claim 2 (depends on 1)

The semiconductor laser device according to claim 1, wherein the length of the phase shift region is 100 times or more of the standard period.

### Claim 3 (depends on 1)

The semiconductor laser device according to claim 1, wherein a length of the first region is shorter than that of the second region.

### Claim 4 (depends on 1)

The semiconductor laser device according to claim 1, wherein the period of the third diffraction grating in the phase shift region is a period shifted by 1% or more with respect to a period of the passive reflective mirror.

### Claim 5 (depends on 1)

The semiconductor laser device according to claim 1, wherein a coupling coefficient of the first diffraction grating in the distributed reflective portion is larger than a coupling coefficient of the second diffraction grating in the first region and a coupling coefficient of the fourth diffraction grating in the second region of the distributed feedback portion.