Preparation method of DFB semiconductor laser capable of working in wide temperature range

Abstract

The invention relates to a preparation method of a DFB semiconductor laser capable of working in a wide temperature range, which comprises the steps of sequentially growing a buffer layer, a lower waveguide structure, a lower electron barrier layer, an InGaAsP and AlGaInAs mixed quantum well, an upper electron barrier layer, an upper waveguide structure, a spacer layer, a long-wavelength grating layer and a grating protection layer on an InP substrate so as to complete the preparation of a primary epitaxial wafer; then preparing a uniform grating on the primary epitaxial wafer, and growing thegrating to form a complete epitaxial wafer; and preparing a DFB laser by adopting a conventional ridge waveguide structure process to realize the DFB semiconductor laser working in a wide temperaturerange. According to the invention, the InGaAsP and AlGaInAs mixed quantum well is adopted, the characteristics of high limiting efficiency of an AlGaInAs high-temperature carrier and small temperature drift coefficient of an InGaAsP quantum well gain spectrum are fully utilized to realize single-mode operation of the laser in a wide temperature range, and the long-wavelength grating layer with absorption characteristics is introduced at the same time to increase the absorption of the grating to the FP mode gain, thereby further inhibiting FP oscillation initiation, and realizing the single-mode laser chip capable of working in a wide temperature range.

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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