Semiconductor laser and production method for a semiconductor laser

Patent metadata

Field	Value
Publication number	US-2021391685-A1
Application number	US-201917284997-A
Country	US
Kind code	A1
Filing date	Oct 4, 2019
Priority date	Oct 15, 2018
Publication date	Dec 16, 2021
Grant date	—

Abstract

In one embodiment, the invention relates to a semiconductor laser comprising a semiconductor layer sequence for generating laser radiation. According to the invention, the semiconductor layer sequence has a geometric structuring on a top side. A resonator is located in the semiconductor layer sequence and is delimited by opposing facets, wherein the facets contain optically active resonator end faces. The structuring ends spaced apart from the facets. The resonator end faces are spaced apart from material removals from the semiconductor layer sequence.

First claim

1 . A semiconductor laser with a semiconductor layer sequence for generating laser radiation, wherein
the semiconductor layer sequence comprises at least one geometric structuring on a top side a resonator in the semiconductor layer sequence is bounded by two opposing facets of the semiconductor layer sequence, so that the facets comprise optically effective resonator end faces, the structuring ends at a distance from at least one of the facets, and at least one of the resonator end faces is spaced apart from material removals from the semiconductor layer sequence.

2 . The semiconductor laser according to claim 1 ,
wherein the facets are smooth planar surfaces produced by means of breaking, wherein the facets are rectangular in a plan view on the facets.

3 . The semiconductor laser according to claim 1 ,
in which the structuring comprises a ridge waveguide which comprises a broadening towards each of the facets, so that the semiconductor laser is a refractive index guided laser, wherein the broadenings at the facets extend over an entire width of the semiconductor layer sequence at the top side.

4 . The semiconductor laser according to claim 3 ,
in which the broadenings are trapezoidal and/or funnel-shaped as seen in a plan view of the top side.

5 . The semiconductor laser according to claim 3 ,
in which each broadening is limited to a region directly at the facets, and the ridge waveguide outside the broadening comprises a constant, uniform width, wherein a length of each broadening is at most 10% of a length of the resonator.

6 . The semiconductor laser according to claim 1 ,
wherein the semiconductor laser is a gain-guided laser without refractive index guidance.

7 . The semiconductor laser according to claim 6 ,
in which the patterning comprises at least two trenches for reflecting away parasitic laser modes, wherein the trenches extend along the resonator.

8 . The semiconductor laser according to claim 1 ,
wherein the structuring comprises at least one H-shaped protrusion as seen in a plan view of the top side, wherein a center bar of said H extends along the resonator.

9 . The semiconductor laser according to the preceding claim 8 ,
wherein the H is asymmetrically shaped as seen in a plan view, such that the center bar and the resonator are eccentrically located in the top side.

10 . The semiconductor laser according to claim 1 ,
in which the structuring comprises a frame which bounds the semiconductor layer sequence on the top side all around, wherein a maximum thickness of the semiconductor layer sequence is present at the frame.

11 . The semiconductor laser according to claim 1 ,
wherein an acoustic layer is provided on at least one of the facets on the top side of the semiconductor layer sequence, wherein the acoustic layer has a lower sound velocity than the semiconductor layer sequence, wherein the acoustic layer is arranged at a distance from electrical contact pads of the semiconductor laser and is limited to a strip at the associated facet.

12 . The semiconductor tor laser according to claim 1 ,
in which, at the facets and as seen in a plan view of the facets, a distance of the optically effective resonator end faces, which are configured for reflection and/or for coupling out the laser radiation generated in operation, towards a material removal out of the semiconductor layer sequence is at least 40 μm and/or at least one fivefold of a mean diameter of the resonator end faces.

13 . The semiconductor laser according to claim 1 ,
wherein an initiator region is generated at at least one of the facets and spaced apart from the associated resonator end face, which initiator region is configured as an initial region for breaking the semiconductor layer sequence, wherein the said facet comprises a greater roughness at the initiator region than at the associated resonator end face.

14 . The semiconductor laser according to claim 1 ,
which comprises a plurality of resonators, so that the semiconductor laser is a laser bar with a plurality of laser units.

15 . The semiconductor laser according to claim 1 ,
further comprising a carrier with a carrier structure, wherein the semiconductor layer sequence is attached to the carrier at the top side, wherein the carrier structure corresponds to the structuring of the semiconductor layer sequence, so that the carrier and the semiconductor layer sequence can be adjusted to each other with a lateral tolerance of at most 5 μm.

16 . A production method for semiconductor lasers according to claim 1 comprising the steps:
growing the semiconductor layer sequence,
structuring the semiconductor layer sequence by material removal, so that the at least one geometric structuring is formed, and
generating the facets by breaking,
wherein the breaking takes place only in those regions of the semiconductor layer sequence from which no material of the semiconductor layer sequence was previously removed.

17 . The method according to claim 16 , by which a semiconductor laser comprising an initiator region is produced,
wherein the initiator regions are generated by means of laser irradiation, such that the top side and a bottom side of a growth substrate for the semiconductor layer sequence are planar at the facets.

18 . A semiconductor laser with a semiconductor layer sequence for generating laser radiation, wherein
the semiconductor layer sequence comprises at least one geometric structuring on a top side a resonator in the semiconductor layer sequence is bounded by two opposing facets of the semiconductor layer sequence, so that the facets comprise optically effective resonator end faces, the at least on geometric structuring ends at a distance from at least one of the facets, at least one of the resonator end faces is spaced apart from material removals from the semiconductor layer sequence, and an acoustic layer is provided on at least one of the facets on the top side of the semiconductor layer sequence, wherein the acoustic layer has a lower sound velocity than the semiconductor layer sequence.

Assignees

• Osram Opto Semiconductors Gmbh

Inventors

• Ali Muhammad
• König Harald
• Gerhard Sven
• Lell Alfred

Classifications

• H01S5/32341

  blue laser based on GaN or GaP · CPC title

• H01S5/22

  having a ridge or stripe structure · CPC title

• H01S2301/166

  Single transverse or lateral mode · CPC title

• H01S5/34333

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

• H01S5/24

  having a grooved structure, e.g. V-grooved {, crescent active layer in groove, VSIS laser} · CPC title