Flared laser oscillator waveguide

Patent metadata

Field	Value
Publication number	US-2017222402-A1
Application number	US-201615377813-A
Country	US
Kind code	A1
Filing date	Dec 13, 2016
Priority date	Apr 9, 2013
Publication date	Aug 3, 2017
Grant date	—

Abstract

A broad area semiconductor diode laser device includes a multimode high reflector facet, a partial reflector facet spaced from said multimode high reflector facet, and a flared current injection region extending and widening between the multimode high reflector facet and the partial reflector facet, wherein the ratio of a partial reflector facet width to a high reflector facet width is n:1, where n>1. The broad area semiconductor laser device is a flared laser oscillator waveguide delivering improved beam brightness and beam parameter product over conventional straight waveguide configurations.

First claim

What is claimed is:

1 . A broad area semiconductor diode laser device comprising:
a multimode high reflector facet; a partial reflector facet spaced from said multimode high reflector facet; and a flared current injection region extending and widening between said multimode high reflector facet and said partial reflector facet, wherein the ratio of a partial reflector facet width to a high reflector facet width is n:1, where n>1.

2 . The device of claim 1 wherein said flared current injection region propagates light such that a beam output at said partial reflector facet has a narrower beam width than said partial reflector facet width and a corresponding narrower slow-axis divergence.

3 . The device of claim 2 wherein said substantially narrower beam width and slow-axis divergence in conjunction with an enlarged total pumped area provided by the flaring of said flared current injection region are operable to reduce thermal resistance and electrical series resistance and result in increased beam brightness and lower beam parameter product of said beam output for a selected device output power.

4 . The device of claim 1 wherein said high reflector facet has a width selected in the range of about 10 μm to 200 μm.

5 . The device of claim 1 wherein said flared current injection region flares with a constant change in width with respect to length.

6 . The device of claim 1 wherein said flared current injection region flares with a variable change in width with respect to length.

7 . The device of claim 1 wherein said flared current injection region flares with a plurality of flare regions.

8 . The device of claim 1 wherein said current injection region includes a rectangular end portion positioned at said multimode high reflector facet allowing a cleave to be formed in said rectangular end portion providing a predictable width for said multimode high reflector facet.

9 . The device of claim 1 wherein said current injection region includes a rectangular end portion positioned at said multimode partial reflector facet allowing a cleave to be formed in said rectangular end portion providing a predictable width for said multimode partial reflector facet.

10 . The device of claim 1 wherein said flared current injection region is gain guided.

11 . The device of claim 1 wherein said flared current injection region is index guided.

12 . The device of claim 1 wherein said ratio of facet widths is optimized for brightness over a selected current range.

13 . The device of claim 1 further comprising a pair of scattering elements disposed along opposing lateral sides of said flared current injection region, said scattering elements operable to scatter higher order modes of light propagating therein.

14 . The device of claim 1 further comprising a distributed feedback grating disposed in said flared current injected region and extending between said facets, said distributed feedback grating providing wavelength stabilization to the device.

15 . The device of claim 1 further comprising a distributed Bragg reflector grating positioned at said high reflector facet, said distributed Bragg reflector providing wavelength stabilization to the device.

16 . The device of claim 1 wherein a beam is emitted substantially in the fundamental mode across a fast axis thereof.

17 . The device of claim 1 wherein said multimode high reflector facet has a reflectivity of about 90% or greater.

18 . The device of claim 1 wherein said partial reflecting facet has a reflectivity of about 0.05% or greater.

19 . A multimode flared laser oscillator waveguide comprising:
a semiconductor gain volume having a multimode high reflector and an output coupler oppositely disposed and spaced apart by a resonator length, top and bottom oppositely disposed sides spaced apart by a resonator height, and first and second oppositely disposed flared sides spaced apart by a variable resonator width providing said high reflector with a shorter width than said output coupler.

20 . A flared laser oscillator waveguide comprising:
a semiconductor gain volume including:
a high reflector surface and an opposing partial reflector surface spaced apart from each other by a resonator length;
top and bottom opposite surfaces spaced apart by a resonator height; and
first and second opposite side surfaces spaced apart by a resonator width wherein at least a portion of said opposite side surfaces are spaced apart by a variable resonator width forming a flared oscillator region and providing said high reflector surface with a shorter width than said partial reflector surface.

Assignees

• Nlight Inc

Inventors

• Kanskar Manoj

Classifications

• H01S5/1237

  Lateral grating, i.e. grating only adjacent ridge or mesa · CPC title

• H01S2301/16

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

• H01S5/1014

  Tapered waveguide, e.g. spotsize converter (H01S5/1064 takes precedence) · CPC title

• H01S2301/18

  Semiconductor lasers with special structural design for influencing the near- or far-field · CPC title

• H01S5/1203

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