Gradually doped wide waveguide interband cascaded laser and its preparation method

Abstract

The invention discloses a gradually doped wide waveguide interband cascade laser and a preparation method thereof, wherein the gradually doped wide waveguide interband cascade laser comprises: a substrate; Layer, lower respectively confinement layer, cascade region, upper respectively confinement layer, upper waveguide cladding, and upper contact layer; wherein, the thickness of the lower respectively upper confinement layer is on the order of hundreds of nanometers to microns, and the lower respectively Both the confinement layer and the upper confinement layer are gradually doped, so that the doping concentration at both ends of the lower confinement layer and the upper confinement layer is relatively high, and the doping concentration in the central region is relatively low. The graded doped wide waveguide interband cascade laser effectively improves the optical confinement factor and increases the optical gain; effectively reduces the voltage drop on the heterojunction surface, improves the photoelectric efficiency, reduces free carrier absorption, and reduces the loss of the device ; And can reduce the operating voltage, improve work efficiency.

Description

technical field [0001] The disclosure belongs to the field of mid-infrared semiconductor lasers, and relates to a gradually doped wide waveguide interband cascaded laser and a preparation method thereof. Background technique [0002] In the infrared band, the 2μm-5μm band is a very important atmospheric window. The absorption peaks of many atoms and molecular gases are within this band, including water molecules, methane, hydrogen chloride and other gases. The absorption peak of water molecules is 2.7 μm, the absorption peak of methane is 3.41 μm, and the absorption peak of hydrogen chloride gas is 3.54 μm, especially some toxic and harmful gases, such as CO, CH 4 , NO 2 etc., the absorption peak in this band is strong, so this band is suitable for environmental monitoring. [0003] Absorption spectroscopy (TDLAS) and photoacoustic spectroscopy (PAS) based on mid-infrared lasers have broad application prospects in the fields of industrial gas online analysis, environmental...

AI Technical Summary

Problems solved by technology

However, since the cascading region of existing interband cascaded lasers is composed of multiple layers and materials, its average refractive index is low, resulting in insufficient optical confinement at the center of the laser, and a low optical confinement factor. Conducive to the improvement of laser performance

Images