Wavelength-locked high-efficiency semiconductor laser and preparation method thereof

Abstract

The invention discloses a wavelength-locked high-efficiency semiconductor laser, and belongs to the technical field of semiconductor laser devices. The laser comprises an N-type lower limiting layer, an N-type lower waveguide layer, a quantum well active layer, a P-type upper waveguide layer, an insertion layer, a P-type upper limiting layer and a P-type contact layer from an N-type substrate layer to the top in sequence, the refractive index of the insertion layer is the same as that of the P-type waveguide layer, the conduction type of the insertion layer is N-type, a current limiting layer is formed in the slow axis direction, meanwhile, a grating is formed in the resonance direction, current injection and the grating are formed by etching the insertion layer, and then the P-type upper limiting layer and the P-type contact layer are grown through a secondary epitaxial process. A high-reflection film is evaporated on the rear cavity surface of the laser, and an anti-reflection film is evaporated on the front cavity surface of the laser. The grating is integrated on a laser sheet, meanwhile, good lateral current limitation is formed, the grating and the current limiting layer adopt the same process, the preparation process is simplified, and the laser has the advantages of wavelength locking and high electro-optical efficiency.

Description

technical field [0001] The invention belongs to the technical field of semiconductor laser devices, and in particular relates to a wavelength-locked high-efficiency semiconductor laser and a preparation method thereof. Background technique [0002] Semiconductor lasers are widely used in pumping solid-state and fiber lasers, material processing, and laser medical treatment due to their advantages such as compact structure, low cost, and easy control of the optical field. At present, many application scenarios require semiconductor lasers to have the characteristics of high efficiency and narrow spectral width. [0003] One of the important factors affecting the efficiency of semiconductor lasers is the lateral current spread. Since the doping of the P-type confinement layer and the contact layer is relatively high and the electrical conductivity is low, it is easy to generate lateral expansion under high current density injection, resulting in a decrease in current injectio...

AI Technical Summary

Problems solved by technology

Due to the relatively high doping of the P-type confinement layer and the contact layer, the conductivity is low, and it is easy to produce lateral expansion under high current density injection, resulting in a decrease in current injection efficiency.

By etching the material on both sides of the ridge, the current spread can be suppressed, but at the same time, problems such as increased lateral divergence angle, increased stress, and polarization degradation

[0004] On the other hand, external cavity feedback can be used for wavelength locking, but there are problems of increased volume and system instability, making it difficult to be widely used

[0005] The method of preparing gratings on a chip can greatly improve the integration level. The common method is to form gratings by etching deep grooves when preparing chips, but the process is difficult and the loss of gratings is high.

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