Device and method for testing nonlinear polarization coefficient and absorption coefficient at terahertz band

Abstract

The invention relates to a device and a method for testing a nonlinear polarization coefficient and an absorption coefficient at a terahertz band. Laser is split into one path of pump light and one path of probe light by a beam splitter, wherein the probe light is reflected by a reflector group with an adjustable light path, is attenuated by a metal attenuation piece used for adjusting the beam intensity of incident laser and then is reflected to a high resistance silicon chip by the reflector; the pump light split by the beam splitter is reflected to enter a terahertz generation device so as to generate terahertz collimating light and the generated terahertz collimating light is focused on a sample rack at a focus position by a parabolic mirror by virtue of a terahertz polarizing plate, and the terahertz is converted into parallel light which is reflected to the high resistance silicon chip by another parabolic mirror; and the two paths of light are coincided at the high resistance silicon chip, are focused to a detection crystal by the parabolic mirrors, are focused to reach a Wollaston prism by virtue of a 1 / 4 wave plate after being scattered by using a convex lens and are respectively focused to two photoelectric detectors. A test sample only needs to be arranged at the position of the sample rack or the detection crystal in a light path, namely the nonlinear polarization coefficient and the absorption coefficient of the sample at the terahertz band can be tested.

Description

technical field [0001] The invention relates to a nonlinear crystal characteristic testing technology, in particular to a device and method for testing the nonlinear polarization coefficient and absorption coefficient of the nonlinear crystal in the terahertz band. Background technique [0002] Nonlinear crystals generally have good optical transmittance and high effective nonlinear electric polarization coefficient, and their refractive index changes with the change of external working conditions. Nonlinear crystal materials are widely used in optical systems such as lasers. They are indispensable optical materials, and to a large extent limit the development and application of modern optical technologies such as lasers. Therefore, the measurement of nonlinear polarization coefficient of samples is very important. important research significance. [0003] At present, although nonlinear crystals are widely used, there are very few methods for testing the nonlinear polarizat...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims at the problems that current methods for testing the nonlinear polarization coefficient of nonlinear crystals are relatively complicated and the testing efficiency is low, and proposes a device and method for testing the nonlinear polarization coefficient and absorption coefficient in the terahertz band. The test sample is placed at different positions in the optical path to realize the test of the nonlinear polarization coefficient of the sample in the terahertz band and the absorption coefficient of the terahertz band

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