Mid-infrared semiconductor saturable absorber mirror based on INAS/GASB superlattice and preparation method thereof

Patent metadata

Field	Value
Publication number	US-12489268-B2
Application number	US-202218059935-A
Country	US
Kind code	B2
Filing date	Nov 29, 2022
Priority date	Jan 4, 2021
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A mid-infrared semiconductor saturable absorber mirror based on InAs/GaSb superlattice comprises a GaSb substrate with an anti-reflection film coated on the lower surface of the GaSb substrate; InAs/GaSb superlattice which has a specific structure and thickness and is arranged on the GaSb substrate; and Bragg reflection film which is arranged on the InAs/GaSb superlattice, wherein Bragg reflection film is composed of multiple pairs of ZnS and YbF 3 film layers with a thickness of ¼ wavelength, and the YbF 3 film layer is connected with the InAs/GaSb superlattice. The device not only has a mid-infrared working range with a broadband operation bandwidth, but also has the advantages of designable parameters, outstanding robustness, high damage threshold and the like, and sets a foundation for the development of mid-infrared ultrafast mode-locked lasers.

First claim

We claim:

1 . An InAs/GaSb superlattice-based mid-infrared semiconductor saturable absorber mirror, comprising:
a GaSb substrate having a lower surface, the GaSb substrate being coated with an anti-reflection film on the lower surface; an InAs/GaSb superlattice arranged on the GaSb substrate; Bragg reflection film arranged on the InAs/GaSb superlattice and having an upper surface; wherein Bragg reflection film is composed of multiple pairs of ZnS and YbF 3 film layers, and the YbF 3 film layer is connected with the InAs/GaSb superlattice.

2 . The InAs/GaSb superlattice-based mid-infrared semiconductor saturable absorber mirror according to claim 1 , wherein the upper surface of Bragg reflection film is bonded with a heat sink.

3 . The InAs/GaSb superlattice-based mid-infrared semiconductor saturable absorber mirror according to claim 1 , wherein the InAs/GaSb superlattice comprises a GaSb layer and an InAs layer growing alternately;
an InSb transitional layer is contained between the GaSb layer and the InAs layer to reduce the lattice mismatch; the InAs/GaSb superlattice has 20-100 periods; the thickness of InAs and GaSb in each period is 5-30 atomic layers to cover the mid-IR spectral region; and a specific thickness is determined according to a laser wavelength and a material absorption coefficient of the superlattice.

4 . The InAs/GaSb superlattice-based mid-infrared semiconductor saturable absorber mirror according to claim 1 , wherein the InAs/GaSb superlattice is located at a wave peak position of a standing wave light field.

5 . The InAs/GaSb superlattice-based mid-infrared semiconductor saturable absorber mirror according to claim 1 , wherein Bragg reflection film is formed by stacking periodic YbF 3 /ZnS films, and a thickness of the YbF 3 or ZnS film is a quarter of a laser center wavelength.

6 . A method for preparing the InAs/GaSb superlattice-based mid-infrared semiconductor saturable absorber mirror of claim 1 , comprising:
(1) polishing a GaSb semiconductor baseplate to obtain a GaSb substrate; (2) alternately growing an InAs nanolayer, an InSb transitional layer and a GaSb nanolayer with a short-period structure on the Gasb substrate by adopting a molecular beam epitaxy technology to form the InAs/GaSb superlattice; (3) coating a surface of the InAs/GaSb and a surface of the substrate respectively with Bragg reflection film and an anti-reflection film by using a vacuum ion beam sputtering technology; and (4) pasting a prepared sample on metal heat sink with high heat conductivity through heat conducting adhesive to prepare the mid-IR SESAM.

Assignees

• Univ Shanghai Jiaotong
• Shanghai Inst Tech Physics Cas

Inventors

• Xie Guoqiang
• Qin Zhipeng
• Zhou Yi
• Chen Jianxin

Classifications

• H01S3/08059

  Constructional details of the reflector, e.g. shape (mirrors in general G02B5/08; mountings for mirrors G02B7/18) · CPC title

• H01S3/0405

  Conductive cooling, e.g. by heat sinks or thermo-electric elements · CPC title

• H01S3/173

  fluoride glass, e.g. fluorozirconate or ZBLAN [ ZrF4-BaF2-LaF3-AlF3-NaF] · CPC title

• H01S3/0401

  of optical elements being part of laser resonator, e.g. windows, mirrors, lenses · CPC title

• H01S3/067

  Fibre lasers · CPC title