Semiconductor light-emitting device and optical device

Patent metadata

Field	Value
Publication number	US-10958036-B2
Application number	US-201816174523-A
Country	US
Kind code	B2
Filing date	Oct 30, 2018
Priority date	Nov 2, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A semiconductor light-emitting device includes an active layer including quantum dots, a diffraction grating, a low-reflectance film disposed at a light-emitting end of the active layer, and a high-reflectance film disposed at another end of the active layer and having an optical reflectance higher than an optical reflectance of the low-reflectance film.

First claim

What is claimed is:

1. A semiconductor light-emitting device, comprising:
an active layer including quantum dots;
a diffraction grating;
a low-reflectance film disposed at a light-emitting end of the active layer; and
a high-reflectance film disposed at another end of the active layer and having an optical reflectance higher than an optical reflectance of the low-reflectance film,
wherein the semiconductor light-emitting device is a distributed-feedback (DFB) laser diode; and
the optical reflectance of the high-reflectance film is greater than or equal to 80% at a DFB wavelength and is less than or equal to 50% at a gain peak wavelength of the quantum dots of the active layer.

2. The semiconductor light-emitting device as claimed in claim 1 , wherein the optical reflectance of the low-reflectance film is greater than or equal to 1% and less than or equal to 10%.

3. An optical device, comprising:
a semiconductor light-emitting device;
an optical modulator that modulates light emitted from the semiconductor light-emitting device; and
an emitter that emits light received from the optical modulator,
wherein the semiconductor light-emitting device includes
an active layer including quantum dots,
a diffraction grating,
a low-reflectance film disposed at a light-emitting end of the active layer, and
a high-reflectance film disposed at another end of the active layer and having an optical reflectance higher than an optical reflectance of the low-reflectance film,
wherein the semiconductor light-emitting device is a distributed-feedback (DFB) laser diode; and
wherein the optical reflectance of the high-reflectance film is greater than or equal to 80% at a DFB wavelength and is less than or equal to 50% at a gain peak wavelength of the quantum dots of the active layer.

4. The optical device as claimed in claim 3 , further comprising:
an optical receiver; and
an entrance part that causes light to enter the optical receiver.

5. The optical device as claimed in claim 3 , wherein the optical reflectance of the low-reflectance film is greater than or equal to 1% and less than or equal to 10%.

6. The optical device as claimed in claim 3 , further comprising:
an optical waveguide that optically connects the semiconductor light-emitting device to the optical modulator, wherein
the optical waveguide includes an end face facing the semiconductor light-emitting device; and
an optical mode shape of the optical waveguide at the end face matches an optical mode shape of the semiconductor light-emitting device.

7. The optical device as claimed in claim 6 , wherein the optical waveguide includes an end portion whose width gradually decreases toward the end face.

8. The optical device as claimed in claim 6 , further comprising:
a refractive index matching material that fills a gap formed between the semiconductor light-emitting device and the optical waveguide.

Assignees

• Fujitsu Ltd
• Photonics Electronics Technology Res Ass

Inventors

• Hatori Nobuaki

Classifications

• H01S5/0287 Primary

  Facet reflectivity · CPC title

• H01S5/0288

  Detuned facet reflectivity, i.e. reflectivity peak is different from gain maximum · CPC title

• H01S5/1221

  Detuning between Bragg wavelength and gain maximum · CPC title

• G02B2006/12195

  Tapering · CPC title

• H01S2301/163

  Single longitudinal mode · CPC title