Narrow linewidth distributed feedback semiconductor laser and preparation method thereof

Abstract

A distributed feedback semiconductor laser, the laser comprises an N-face electrode layer, a substrate layer, a buffer layer, a lower waveguide layer, an active layer, an upper waveguide layer, a secondary epitaxial grating layer, and an etching self-stopping layer from bottom to top. , a cladding layer, an ohmic contact layer, a passivation layer and a P-surface electrode layer; the cladding layer and the ohmic contact layer constitute a waveguide structure, and the waveguide structure is a ridge waveguide structure. The present invention utilizes the upper and lower layers of the grating structure in the vertical direction to jointly feed back the mode selection. The secondary epitaxial grating distributed near the active region is coupled with the optical field efficiently to achieve frequency selection and narrow linewidth. The electrode sampling grating has a narrow single reflection peak line width, which is fully coupled and fed back with the optical field in the waveguide, which can further stabilize the working wavelength, improve the side mode suppression ratio, reduce the line width factor, and effectively narrow the laser line width.

Description

technical field [0001] The invention relates to the technical field of semiconductor lasers, in particular to a narrow line width distribution feedback semiconductor laser and a preparation method thereof. Background technique [0002] Narrow linewidth lasers have very broad application prospects in coherent optical communications, lidar, dense wavelength division multiplexing, optical fiber sensing, precision optical measurement, holography and other fields. With the rapid development of optical communication networks and smart travel in recent years, the demand for narrow linewidth lasers has become increasingly prominent. Among them, narrow linewidth semiconductor lasers have the advantages of small size, light weight, high efficiency, long life, direct current drive, narrow spectral linewidth, and good coherence, and become ideal light sources for single longitudinal mode, stable wavelength, and narrow linewidth lasers. . [0003] Narrow linewidth semiconductor lasers ...

AI Technical Summary

Problems solved by technology

However, the linewidth of the general distributed feedback semiconductor laser is on the order of MHz, which cannot meet the applications of high-order coherent optical communication and high-precision detection radar.

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