Terahertz semiconductor laser, its preparation method and application

Abstract

The invention provides a terahertz semiconductor laser device and a preparation method thereof and an application thereof. The terahertz semiconductor laser device comprises a first metal layer, a pressure welding metal layer serving as the bottom of the semiconductor laser device and a heat dissipation channel, a supporting substrate, a first highly-doped layer which is arranged on the supportingsubstrate and serves as a lower waveguide light limiting layer of the laser device, an active region growing on the first highly doped layer, a second highly-doped layer positioned on the active region, a plurality of electrical isolation trenches, an ohmic contact layer, an electrical isolation layer and a second metal layer. The terahertz semiconductor laser device is advantaged in that a periodic multi-ridge array and rectangular cavity coupling structure is adopted, and the beam divergence angle in the ridge width direction of the device is improved by means of the self-imaging effect caused by in-phase interference, by using a periodic multi-ridge array, the gain volume of the laser device is increased, and the output power is improved.

Description

technical field [0001] The invention relates to the field of optical waveguide technology of terahertz band semiconductor laser devices, in particular to a terahertz semiconductor laser, its preparation method and application. Background technique [0002] Since the energy value of electromagnetic waves in the terahertz band (0.3-10THz) corresponds to the rotation and vibration energy of some special gas molecules and water molecules, it has unique application value in gas composition detection, medical diagnosis, dangerous goods telemetry, free space communication, etc. Terahertz quantum cascade laser (Quantum Cascade Laser, QCL) is a unipolar terahertz semiconductor laser based on coupled multi-quantum well conduction band sublevel stimulated emission luminescence, which has the characteristics of miniaturization, portability and high continuous power. , has gradually become an ideal terahertz coherent light source for the above applications, so it is of great significance...

AI Technical Summary

Problems solved by technology

In order to improve the beam quality of the device while increasing the output power of the device, tree array QCL, photonic crystal (Photonic Crystal, PC) QCL, master oscillator power amplifier (Master-oscillator Power-amplifier, MOPA) QCL and oblique New devices such as cavity QCL, in which the tree-shaped array quantum cascade laser composed of Y-shaped units is output in the same phase mode, realizing a single lobe in the far field, but the device power is low and the threshold current density is high

In addition, regarding the production of PC DFB (photonic crystal distributed feedback) quantum cascade lasers, the peak power of the single-cavity surface of the device is relatively high, and the far-field divergence angle near the diffraction limit is obtained, but due to the existence of multiple band-edge modes in the photonic crystal , the device is a dual longitudinal mode laser

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