Distributed feedback laser

Abstract

The invention relates to the technical field of a semiconductor laser, and provides a novel distributed feedback laser adopting uniform optical grating and capable of realizing single modes. The laser comprises an active region and a reflecting region; current is injected to the active region for providing gain for the laser; the outer end plane of the reflecting region is plated with an antireflection film or provided with an anti-reflection structure for reducing reflection; and the other end of the active region is the output end plane of the laser, and the end plane is plated with the anti-reflection film for reducing reflection. The optical grating in the reflecting region can increase the feedback of the laser and reduce threshold value gain under a short cavity length; the optical grating in the active region and the reflecting region is continuously and uniformly distributed feedback Bragg grating; the optical grating periods of the active region and the reflecting region are equivalent; and an effective refractivity difference between the active region and the reflecting region is realized through current injection for performing mode selection. According to the distributed feedback laser with uniform optical grating, the single mode is realized; the distributed feedback laser has a relatively low threshold value gain under the short cavity length; and meanwhile, the distributed feedback laser is low in manufacturing difficulty.

Description

technical field [0001] The invention belongs to the technical field of semiconductor lasers and relates to distributed feedback lasers. Background technique [0002] With the development of high-capacity ultra-high-speed optical fiber communication technology, semiconductor lasers with high direct modulation rates have grown into one of the key devices for optical fiber communication systems and next-generation optical networks. In wavelength division multiplexing (WDM) systems, 25Gb / s high-speed direct modulation lasers can be used to form transmitters for 100Gb / s next-generation Ethernet. In the development of local area network, the high-speed direct modulation laser with 25GHz modulation bandwidth is the key device to realize 40Gb / s optical fiber communication, among which the distributed feedback (Distributed Feedback, DFB) laser is favored at home and abroad due to its high power and good single longitudinal mode characteristics. Extensive attention and research. [...

AI Technical Summary

Problems solved by technology

However, the manufacturing process becomes very complicated, mainly because the integration of passive waveguides at both ends requires docking regrowth technology, which is technically difficult and complex.

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