Distributed feedback laser with short cavity length

Abstract

The invention relates to the technical field of semiconductor lasers, and provides a distributed feedback laser with a short cavity length. The laser contains two parts, i.e., a gain region and a reflection region; a metal electrode exists in the gain region, current needs to be injected to provide a gain for the laser; a grating layer of the gain region is a distributed feedback Bragg grating containing a lambda / 4 phase shift region; one end of the gain region is the reflection region which contains a core layer structure which is the same as that of the gain region, i.e., a waveguide transmission layer is also an active quantum well material, but current is not injected to the region; a grating layer of the reflection region is formed by evenly distributed Bragg gratings; an outer end face of the reflection region is plated with an antireflection film or adopts an antireflection structure to reduce reflection; and the other end of the gain region is an output end face of the laser, and the end face is plated with an antireflection film to reduce reflection. The scheme of the laser can enable the laser to still have a relatively low threshold gain and a good side-mode suppression ratio when the cavity length is relatively short, and the laser has the characteristic of small manufacture difficulty at the same time.

Description

technical field [0001] The invention belongs to the technical field of semiconductor lasers, and relates to a distributed feedback laser with a λ / 4 phase shift. 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 dense wavelength division multiplexing (DWDM) 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 them, the distributed feedback (Distributed Feedback, DFB) laser is popular at home and abroad because of its high power and good single longitudinal mode characteristics. ex...

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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