Fabrication method for integrated semiconductor laser

Abstract

The invention discloses an integrated semiconductor laser of a 2-micrometer single-mode high-power GaSb-based metal grating master oscillator power amplifier and a fabrication method of the integrated semiconductor laser. The semiconductor laser comprises a substrate, an epitaxial structure, a gain amplification region, a master oscillator region, a metal grating region and light limitation grooves, wherein the epitaxial structure is grown on the substrate and comprises an N-type lower contact layer, an N-type lower limitation layer, a lower waveguide layer, an active region, an upper waveguide layer, a P-type upper limitation layer and a P-type upper contact layer from bottom to top, the gain amplification region is arranged at the front part, namely an emergent light part of the semiconductor laser and is of an isosceles trapezoid structure formed by downwards etching the P-type upper contact layer, the master oscillator region is arranged at the rear part of the gain amplification region and is of a ridged waveguide structure formed by downwards etching the P-type upper contact layer and the P-type upper limitation layer, the metal grating region is arranged at the rear part of the master oscillator region and is of a periodic grating structure formed on the surface of the upper waveguide layer, the light limitation grooves are symmetrically arranged at the two sides of ridged waveguide structure, and the light limitation grooves and the ridged waveguide structure are arranged in an inclining manner.

Description

technical field [0001] The invention relates to a mid-infrared semiconductor laser, in particular to a preparation method of a 2μm single-mode high-power GaSb-based metal grating main oscillation power amplifier (MOPA) integrated semiconductor laser. Background technique [0002] The 2-5μm band contains a very important atmospheric window, including the characteristic spectral lines of many gas molecules, which can be widely used in civil projects such as air pollution monitoring and gas detection; and high-power lasers working in this band can be expected to be used in lidar, It can play a better application effect in military projects such as photoelectric countermeasures. Traditional Si-based and GaAs-based materials have relatively wide band gaps and cannot meet the requirements for wavelength. The relatively narrow bandgap of GaSb material has inherent advantages. However, most F-P cavity semiconductor lasers with common structures work in multimode, and spectral broad...

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Problems solved by technology

[0003] The common methods to achieve single longitudinal mode wavelength stabilization are DFB structure and DBR structure. For GaSb-based materials, the problem of easy oxidation caused by the high aluminum component in the waveguide layer and confinement layer makes the traditional burial method that requires secondary epitaxy. The production of grating DFB is very difficult

GaSb-based DFB uses the ridge waveguide and Bragg grating in the epitaxial layer to complete the refractive index guidance and gain guidance of light. However, in order to ensure the single-mode operation of the laser, the width of the ridge waveguide is on the order of several microns, and its The light output area is small, the optical power density is high, and it is easy to cause catastrophic optical mirror damage (COMD) on the cavity surface, which is not conducive to the stable operation of the laser, and its output power is also limited to a lower range, which improves the output of semiconductor lasers. The most power-effective method is to increase the strip width of the ridge waveguide region. However, the increase of the strip width will affect the stability of the single mode of the laser, and cannot guarantee the operation of the single transverse mode and single longitudinal mode. The light output can be improved on the narrow ridge waveguide The power is easy to cause optical catastrophe, the research of high-power single-mode laser is a hot issue

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