DFB semiconductor laser

Abstract

The invention discloses a DFB semiconductor laser, and belongs to the field of semiconductor devices, the DFB semiconductor laser comprises an n-surface electrode, a substrate, an n-type lower cladding, an active region, a grating layer, a p-type upper cladding, a ridge waveguide and a p-surface electrode which are sequentially epitaxially grown from bottom to top, and the active region is of a multi-quantum well structure; groove regions which are symmetrical to each other are etched on the two sides of the ridge waveguide, and the groove regions penetrate through the active region and are used for improving the modulation bandwidth of the DFB semiconductor laser. At normal temperature, the double-trench region improves the relaxation oscillation frequency by improving a light field limiting factor and reduces parasitic capacitance, and at high temperature, the double-trench region improves the relaxation oscillation frequency by reducing carrier diffusion, so that the modulation bandwidth can be improved at both the normal temperature and the high temperature. The manufacturing process is simple, the groove area is far away from a light field, the reliability problem caused by etching of an aluminum-containing material is avoided, and the modulation bandwidth of the DFB semiconductor laser is improved on the basis that the performance and reliability of the laser are not affected.

Description

technical field [0001] The invention belongs to the field of semiconductor devices, and more specifically relates to a DFB semiconductor laser. Background technique [0002] Directly modulated semiconductor lasers have the advantages of low cost, small size, and mass production, and are widely used in low-cost optical fiber communications. With the increasing demand for data transmission rates and the huge demand of data centers, high-speed distributed feedback semiconductor lasers have become the core light source. However, the modulation bandwidth of distributed feedback semiconductor lasers is limited by laser parasitic constants, damping, and relaxation oscillation frequency, and the modulated output optical signal is accompanied by frequency chirp and other phenomena. In addition, as the temperature increases, due to the increase of Auger recombination, the threshold current of the laser increases rapidly, and the differential gain of the laser decreases rapidly, which...

AI Technical Summary

Problems solved by technology

Using a buried heterojunction structure to reduce the width of the active region can effectively increase the modulation bandwidth, but the etching and oxidation of aluminum-containing materials close to the optical field will affect the reliability of the laser, especially the modulation bandwidth at high temperatures is significant Therefore, the industry generally adopts ridge waveguide lasers with simpler processes

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