Nanowire laser structure and fabrication method

Patent metadata

Field	Value
Publication number	US-10374394-B2
Application number	US-201615759977-A
Country	US
Kind code	B2
Filing date	Sep 14, 2016
Priority date	Sep 15, 2015
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

A core-shell nanowire laser structure comprises a substrate ( 12 ), an elongated support element ( 14 ) extending from the substrate, the support element having a first diameter, and an elongated body element ( 16 ) extending on and/or around the support element, the body element having a second diameter at least two times larger than the first diameter, wherein the body element is spaced apart from the substrate.

First claim

What is claimed is:

1. A nanowire laser structure, comprising:
a substrate;
an elongated support element extending from said substrate, said support element having a first diameter; and
an elongated body element extending on and/or around said support element, said body element having a second diameter at least two times larger than said first diameter;
wherein said body element is spaced apart from said substrate;
said nanowire laser structure further comprising a pn junction or a pin junction;
wherein said nanowire laser structure is adapted to emit a laser signal at a wavelength λ,
wherein said first diameter of said support element is smaller than λ/(2n), wherein n denotes an index of refraction of said support element; and

wherein said second diameter of said body element is no smaller than λ/m, wherein m denotes an index of refraction of said body element.

2. The nanowire laser structure according to claim 1 , further comprising a first reflective layer between said body element and said substrate.

3. The nanowire laser structure according to claim 2 , wherein said first reflective layer comprises a distributed Bragg reflector and/or a high contrast grating.

4. The nanowire laser structure according to claim 2 , further comprising a second reflective layer formed above said body element on a side of said body element facing away from said substrate.

5. The nanowire laser structure according to claim 1 , wherein said substrate comprises a waveguide.

6. The nanowire laser structure according to claim 5 , wherein said support element extends from said waveguide.

7. The nanowire laser structure according to claim 1 , further comprising:
an interferometer element optically coupled to said body element, wherein said interferometer element comprises a first laser signal path and a second laser signal path that together form a closed loop;
an output path coupled to said first laser signal path and said second laser signal path; and
a gate element located in said second laser signal path, wherein said gate element is adapted to selectively change a refractive index of said second laser signal path.

8. The nanowire laser structure according to claim 7 , further comprising a feedback path coupling said output path to said gate element.

9. A laser array comprising:
a plurality of nanowire laser structures, each nanowire laser structure of said plurality of nanowire laser structures comprising:
an elongated support element extending from a substrate, said support element having a first diameter; and
an elongated body element extending on and/or around said support element, said body element having a second diameter at least two times larger than said first diameter;

wherein said body element is spaced apart from said substrate;
each said nanowire laser structure further comprising a pn junction or a pin junction;
wherein said nanowire laser structure is adapted to emit a laser signal at a wavelength λ,
wherein said first diameter of said support element is smaller than λ/(2n), wherein n denotes an index of refraction of said support element;
wherein said second diameter of said body element is no smaller than λ/m, wherein m denotes an index of refraction of said body element; and
wherein said substrate of each nanowire laser structure is a common substrate of said plurality of nanowire laser structures.

10. The laser array according to claim 9 , further comprising at least one cooling channel for a cooling medium, said cooling channel extending between adjacent nanowire laser structures of said plurality of nanowire laser structures.

11. A method for forming a nanowire laser structure, comprising:
forming a first reflective layer on a substrate layer;
forming a hole in said first reflective layer, said hole extending to said substrate layer; and
growing a nanowire laser structure in said hole;
wherein growing said nanowire laser structure comprises growing a support element in said hole through said first reflective layer at a first diameter, and extending said support element above said first reflective layer, and growing a body element around at least a portion of said support element that extends above said first reflective layer, said body element having a second diameter at least two times larger than said first diameter;
doping said support element and/or said body element to form a pn junction or a pin junction;
wherein said nanowire laser structure is adapted to emit a laser signal at a wavelength λ, wherein said first diameter of said support element is smaller than λ/(2n), wherein n denotes an index of refraction of said support element; and
wherein said second diameter of said body element is no smaller than λ/m, wherein m denotes an index of refraction of said body element.

12. The method according to claim 11 , wherein said forming said hole comprises a step of forming a first hole in said first reflective layer by anisotropic reactive ion etching, wherein said first hole terminates within said first reflective layer, and afterwards extending said first hole to said substrate layer by chemical etching.

13. The method according to claim 12 , wherein the chemical etching is hydrofluoric acid etching.

Assignees

• Univ Muenchen Tech

Inventors

• Mayer Benedikt
• Koblmueller Gregor
• Finley Jonathan
• Klicpera Johannes
• Abstreiter Gerhard

Classifications

• H01S5/305

  characterised by the doping materials used in the laser structure · CPC title

• H01S3/14

  characterised by the material used as the active medium · CPC title

• G02B6/12004

  Combinations of two or more optical elements · CPC title

• H01S5/0085

  for modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title

• G02F1/225

  in an optical waveguide structure · CPC title