Device and method for implementing terahertz quasi-Gaussian parallel laser beam

Abstract

The invention relates to a device for implementing a terahertz quasi-Gaussian parallel laser beam. The device includes a terahertz quantum cascade laser, an adjustment system movably mounted on a lowtemperature sample frame, an off-axis parabolic mirror mounted on the adjustment system, a movable variable aperture diaphragm arranged outside a cryogenic dewar and a movable terahertz array detectordisposed outside the cryogenic dewar, wherein the terahertz quantum cascade laser is connected with a driving power supply and emits terahertz divergent laser; the off-axis parabolic mirror collectsthe terahertz divergent laser and outputs terahertz quasi-parallel laser beam; the variable aperture diaphragm performs beam optimization on the terahertz quasi-parallel laser beam to form the terahertz quasi-Gaussian parallel laser beam; and the terahertz array detector represents the two-dimensional energy distribution of the terahertz quasi-parallel laser beam and calibrates the collimation ofthe terahertz quasi-parallel laser beam. The invention further relates to a method for implementing the terahertz quasi-Gaussian parallel laser beam. According to the device and method for implementing the terahertz quasi-Gaussian parallel laser beam, the terahertz quasi-Gaussian parallel laser beam which is stable, reliable and excellent in beam quality can be acquired.

Description

technical field [0001] The present invention relates to the technical field of terahertz applications, and more particularly to a device and method for realizing terahertz quasi-Gaussian parallel laser beams. Background technique [0002] Terahertz (THz) laser source is an important radiation source in the field of THz technology. The THz quantum cascade laser (THz QCL) based on semiconductor low-dimensional materials is a very important laser source in the THz frequency band. It has high energy conversion efficiency, volume Small size, stable performance and long service life. Since the size of the laser ridges in the thickness direction is smaller than the laser wavelength, the laser emitted by the THzQCL end face exhibits a divergent characteristic, and the quality of the laser beam is poor. In order to improve the output laser quality of the laser, the existing methods usually use surface grating technology, end face grating technology, super hemispherical high-resistan...

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Problems solved by technology

However, in order to realize the surface grating process, the current and voltage operating characteristics of the device will be affected to varying degrees. Although the quality of the laser beam has been improved, the above-mentioned manufacturing process will lead to a decline in the power performance of the device; the realization of the end face grating process is quite difficult. , and the yield rate of the device process cannot be well guaranteed; in addition, the method of end-face coupling using a hyperhemispherical high-resistance silicon lens has been widely used, but this method will cause the THz laser to be absorbed by the high-resistance silicon lens. The effective laser power output after coupling is reduced, and the output beam still has a certain divergence, which is not a quasi-parallel beam

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