A kind of preparation method of wide temperature working dfb semiconductor laser

Abstract

The invention relates to a preparation method of a DFB semiconductor laser operating at a wide temperature. On an InP substrate, a buffer layer, a lower waveguide structure, a lower electron blocking layer, a mixed quantum well of InGaAsP and AlGaInAs, an upper electron blocking layer, an upper waveguide structure, The spacer layer, the long-wavelength grating layer and the grating protection layer complete the preparation of an epitaxial wafer. Then a uniform grating is prepared on the epitaxial wafer and the grating is regrowth to form a complete epitaxial wafer, and a DFB laser is prepared by using a conventional ridge waveguide structure process to realize a DFB semiconductor laser working at a wide temperature. The invention adopts InGaAsP and AlGaInAs mixed quantum wells, fully utilizes the characteristics of high temperature carrier confinement efficiency of AlGaInAs and the small temperature drift coefficient of InGaAsP quantum well gain spectrum to realize the single-mode operation of the laser in a wide temperature range, and introduces the absorption characteristic The long-wavelength grating layer is used to increase the absorption of the FP mode gain by the grating, and further suppress the FP oscillation, thereby realizing a single-mode laser chip that operates at a wide temperature.

Description

technical field [0001] The invention relates to the field of optical communication, in particular to a preparation method of a wide temperature working DFB semiconductor laser. Background technique [0002] With the rapid development of optical fiber communication, uncooled wide temperature single-mode laser will become the mainstream optical device in the field of optical communication in the future, and it is the key device for long-distance and large-capacity optical fiber communication. It is widely used in fields such as access network and data resurgence. [0003] Usually DFB lasers use InP / InGaAsP and InP / AlGaInAs material systems; due to the high temperature characteristics of InGaAsP quantum wells, InP / InGaAsP lasers usually use buried heterojunction structures, which greatly increases the cost of laser preparation. InP / AlGaInAs generally adopts a ridge structure. However, because the gain curve of AlGaInAs material has a large drift coefficient with temperature, i...

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Problems solved by technology

InP / AlGaInAs generally adopts a ridge structure, but because the gain curve of the AlGaInAs material has a large drift coefficient with temperature, it is difficult to prepare a laser with a wide temperature range

[0004] Generally, InP-based DFB lasers need to work in a wide temperature range without cooling single-mode to ensure the application of the laser in various environments; for ridge waveguide structure lasers, the wavelength of DFB single-mode emission is due to temperature changes. The drift of the AlGaInAs quantum well gain spectrum is around 0.1nm / ℃, and the drift of the gain spectrum of the AlGaInAs quantum well with the temperature is 0.4-0.5nm / ℃. Due to the large wavelength drift deviation between the two, it is difficult for the ridge waveguide structure DFB to work at a wide temperature; and InGaAsP The material gain spectrum varies with temperature at about 0.3-0.4nm / °C. However, in order to improve high temperature characteristics, a more expensive buried structure process is required.

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