Narrow-linewidth distributed feedback semiconductor laser and preparation method thereof

Abstract

The invention provides a distributed feedback semiconductor laser which sequentially comprises an N-surface electrode layer, a substrate layer, a buffer layer, a lower waveguide layer, an active layer, an upper waveguide layer, a secondary epitaxial grating layer, an etching self-stop layer, a cladding layer, an ohmic contact layer, a passivation layer and a P-surface electrode layer from bottom to top. The cladding layer and the ohmic contact layer form a waveguide structure, and the waveguide structure is a ridge waveguide structure. An upper grating structure and a lower grating structure in the vertical direction are used for jointly feeding back mode selection. Secondary epitaxial gratings distributed near the active region are efficiently coupled with a light field so that frequencyselection and line width reduction are realized. The single reflection peak line width of the electrode sampling grating is narrow, the electrode sampling grating is fully coupled with a light field in the waveguide for feedback, the working wavelength can be further stabilized, the side-mode rejection ratio is improved, the line width factor is reduced and the laser line width is effectively narrowed.

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

Images