Semiconductor laser element

Patent metadata

Field	Value
Publication number	US-2025118947-A1
Application number	US-202418910147-A
Country	US
Kind code	A1
Filing date	Oct 9, 2024
Priority date	Oct 10, 2023
Publication date	Apr 10, 2025
Grant date	—

Abstract

A semiconductor laser element includes a semiconductor multilayer portion including an active layer, the semiconductor multilayer portion including (i) a first region including a diffraction grating and (ii) a second region configured to cause laser light to propagate in multiple transverse modes in the second region, the second region including a core region and cladding regions provided on two opposite sides of the core region; at least one electrode disposed on the semiconductor multilayer portion; and a current shielding structure. The semiconductor laser element has a waveguide structure. In a top view, the first region includes a central region where light entering from the second region is propagated and a peripheral region located outward of the central region. In a top view, the current shielding structure is located at a position at least partially overlapping the peripheral region.

First claim

What is claimed is:

1 . A semiconductor laser element, comprising:
a semiconductor multilayer portion comprising an active layer, the semiconductor multilayer portion comprising:
(i) a first region comprising a diffraction grating, and
(ii) a second region configured to cause laser light to propagate in multiple transverse modes in the second region, the second region comprising:
a core region, and
cladding regions located on two opposite sides of the core region;
at least one electrode disposed on the semiconductor multilayer portion; and

a current shielding structure; wherein the semiconductor laser element has a waveguide structure; and in a top view, the first region comprises:
a central region where light entering from the second region is propagated, and
a peripheral region located outward of the central region; and
in a top view, the current shielding structure is located at a position at least partially overlapping the peripheral region.

2 . The semiconductor laser element according to claim 1 , wherein:
the core region has a refractive index n 21 ; the cladding regions have a refractive index n 22 ; the central region has a refractive index n 1 ; laser light emitted from the second region propagates through the first region at a maximum diffusion angle Θ max1 determined by the refractive index n 1 , the refractive index n 21 , and the refractive index n 22 ; and the central region comprises a region located inward of imaginary lines spreading from two opposite ends of an emission end surface of the core region at the maximum diffusion angle Θ max1 .

3 . The semiconductor laser element according to claim 1 , wherein:
the current shielding structure comprises an insulating film located on the semiconductor multilayer portion and comprising an opening portion on the central region; and at least a part of the electrode is located in the opening portion.

4 . The semiconductor laser element according to claim 3 , wherein:
the at least one electrode comprises a first electrode disposed in the opening portion; and the first electrode contacts the semiconductor multilayer portion on an inner side of the opening portion.

5 . The semiconductor laser element according to claim 3 , wherein:
the at least one electrode comprises:
a first electrode disposed on and in contact with the semiconductor multilayer portion, and
a second electrode disposed on the first electrode; and
the second electrode is connected to the first electrode via the opening portion.

6 . The semiconductor laser element according to claim 3 , wherein a width of the opening portion increases toward an emission end surface of the first region.

7 . The semiconductor laser element according to claim 3 , wherein:
the second region comprises a second insulating film disposed on the semiconductor multilayer portion and comprising a second opening portion narrower than the opening portion on the second region; and the electrode is configured to allow a current to be injected into the second region via the second opening portion.

8 . The semiconductor laser element according to claim 1 , wherein:
the current shielding structure comprises an oxide film provided on a surface of the semiconductor multilayer portion and comprising an opening portion on the central region; and the electrode is configured to allow a current to be injected into the central region via the opening portion.

9 . The semiconductor laser element according to claim 8 , wherein the opening portion increases in width toward an emission end surface of the first region.

10 . The semiconductor laser element according to claim 8 , wherein a width of the opening portion is constant.

11 . The semiconductor laser element according to claim 8 , wherein:
the second region comprises a second oxide film disposed in the semiconductor multilayer portion and comprising, on the second region, a second opening portion narrower than the opening portion; and the electrode is configured to allow a current to be injected into the second region via the second opening portion.

12 . The semiconductor laser element according to claim 1 , wherein:
the current shielding structure comprises a block layer provided in the semiconductor multilayer portion and comprising an opening portion on the central region, and the electrode is configured to allow a current to be injected into the central region via the opening portion.

13 . The semiconductor laser element according to claim 12 , wherein a width of the opening portion increases toward an emission end surface of the first region.

14 . The semiconductor laser element according to claim 12 , wherein a width of the opening portion is constant.

15 . The semiconductor laser element according to claim 12 , wherein:
the second region comprises a second block layer located in the semiconductor multilayer portion and comprising, on the second region, a second opening portion narrower than the opening portion; and the electrode is configured to allow a current to be injected into the second region via the second opening portion.

16 . A semiconductor laser element, comprising:
a semiconductor multilayer portion comprising an active layer, the semiconductor multilayer portion comprising:
(i) a first region comprising a diffraction grating, the first region being a slab waveguide, and
(ii) a second region comprising:
a core region, and
cladding regions located on two opposite sides of the core region;
at least one electrode disposed on the semiconductor multilayer portion; and

a current shielding structure; wherein the semiconductor laser element has a waveguide structure; and in a top view, the first region comprises:
a central region where light entering from the second region is propagated, and
a peripheral region located outward of the central region; and
in a top view, the current shielding structure is located at a position at least partially overlapping the peripheral region.

Assignees

• Nichia Corp

Inventors

• Hirose Ryohei
• Masui Shingo
• Ogawa Hisashi

Classifications

• H01S5/2031

  characterized by special waveguide layers, e.g. asymmetric waveguide layers or defined bandgap discontinuities · CPC title

• H01S5/34333

  with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser · CPC title

• H01S5/3213

  asymmetric clading layers · CPC title

• H01S5/1203

  over only a part of the length of the active region · CPC title

• H01S2301/16

  Semiconductor lasers with special structural design to influence the modes, e.g. specific multimode · CPC title