Semiconductor laser element

Patent metadata

Field	Value
Publication number	US-11710941-B2
Application number	US-202117157660-A
Country	US
Kind code	B2
Filing date	Jan 25, 2021
Priority date	Jul 27, 2018
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A semiconductor laser element includes: an n-type cladding layer disposed above an n-type semiconductor substrate (a chip-like substrate); an active layer disposed above the n-type cladding layer; and a p-type cladding layer disposed above the active layer, in which the active layer includes a well layer and a barrier layer, an energy band gap of the barrier layer is larger than an energy band gap of the n-type cladding layer, and a refractive index of the barrier layer is higher than a refractive index of the n-type cladding layer.

First claim

What is claimed is:

1. A semiconductor laser element, comprising:
an n-type cladding layer disposed above an n-type semiconductor substrate;
an active layer disposed above the n-type cladding layer; and
a p-type cladding layer disposed above the active layer, wherein
the active layer includes a well layer and a barrier layer,
an energy band gap of the barrier layer is larger than an energy band gap of the n-type cladding layer, and
a refractive index of the barrier layer is higher than a refractive index of the n-type cladding layer.

2. The semiconductor laser element according to claim 1 , wherein
the n-type cladding layer contains Al x1 Ga 1-x1-y1 In y1 As 1-z1 P z1 ,
the barrier layer contains Al x2 Ga 1-x2-y2 In y2 As 1-z2 P z2 , and
z1>z2 is satisfied.

3. The semiconductor laser element according to claim 2 , wherein
the n-type cladding layer contains Al x1 Ga 1-x1-y1 In y1 , and
the barrier layer contains Al x2 Ga 1-x2-y2 In y2 As.

4. The semiconductor laser element according to claim 3 , wherein
x1<x2 is satisfied.

5. The semiconductor laser element according to claim 1 , wherein
the n-type semiconductor substrate contains GaAs.

6. The semiconductor laser element according to claim 1 , further comprising:
an n-side light guide layer disposed between the n-type cladding layer and the active layer and having a refractive index higher than the refractive index of the n-type cladding layer.

7. The semiconductor laser element according to claim 6 , wherein
the n-side light guide layer includes an (Al x Ga 1-x ) 0.5 In 0.5 P layer.

8. The semiconductor laser element according to claim 1 , further comprising:
a hole barrier layer disposed between the n-type cladding layer and the active layer and having an energy band gap larger than the energy band gap of the n-type cladding layer.

9. The semiconductor laser element according to claim 8 , further comprising:
an n-side light guide layer disposed between the n-type cladding layer and the active layer and having a refractive index higher than the refractive index of the n-type cladding layer.

10. The semiconductor laser element according to claim 9 , wherein
a film thickness of the hole barrier layer is thinner than a film thickness of the n-side light guide layer.

11. The semiconductor laser element according to claim 9 , wherein
the hole barrier layer is disposed between the n-side light guide layer and the active layer.

12. The semiconductor laser element according to claim 9 , wherein
the hole barrier layer is disposed between the n-type cladding layer and the n-side light guide layer.

13. The semiconductor laser element according to claim 9 , wherein
the energy band gap of the hole barrier layer is larger than the energy band gap of the barrier layer.

14. The semiconductor laser element according to claim 9 , wherein
the hole barrier layer is made of an AlGaInP-based semiconductor.

15. The semiconductor laser element according to claim 1 , wherein
an energy band gap of the p-type cladding layer is larger than the energy band gap of the barrier layer.

16. The semiconductor laser element according to claim 1 , wherein
the p-type cladding layer includes a p-type first cladding layer and a p-type second cladding layer, the p-type first cladding layer is disposed closer to the active layer than the p-type second cladding layer is, and
an Al composition ratio of the p-type first cladding layer is lower than an Al composition ratio of the p-type second cladding layer.

17. The semiconductor laser element according to claim 1 , wherein
the energy band gap of the n-type cladding layer is larger than an energy band gap of the n-type semiconductor substrate.

18. The semiconductor laser element according to claim 1 , further comprising:
a buffer layer disposed between the n-type semiconductor substrate and the n-type cladding layer, wherein
the buffer layer contains Al x Ga 1-x As.

19. The semiconductor laser element according to claim 1 , further comprising:
an electron barrier layer disposed between the p-type cladding layer and the active layer and having an energy band gap larger than an energy band gap of the p-type cladding layer.

20. The semiconductor laser element according to claim 19 , wherein
the well layer is made of an InGaAs-based semiconductor.

Assignees

• Nuvoton Technology Corp Japan

Inventors

• Nakatani Tougo
• Hata Masayuki

Classifications

• H01S5/3216 Primary

  quantum well or superlattice cladding layers · CPC title

• H01S5/0206

  Substrates, e.g. growth, shape, material, removal or bonding; (specific crystal orientation H01S5/3202) · CPC title

• H01S5/2009

  by using electron barrier layers · CPC title

• H01S5/2031

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

• H01S5/22

  having a ridge or stripe structure · CPC title