Electro-optic sampling device used for measuring terahertz optical pulse and measuring method thereof

Abstract

The invention is applicable to the terahertz optical field, and provides an electro-optic sampling device used for measuring terahertz optical pulse and a measuring method thereof. The device comprises a polarizer, an electro-optic sampling crystal, a beam splitter, a first phase compensator, a second phase compensator, a first analyzer, a second analyzer and a balanced detector. In the device, the detection light modulated by the terahertz optical pulse is divided into two paths, one of which passes through the first phase compensator and the first analyzer and is received by a first receiver, and the other one passes through the second phase compensator and the second analyzer and is received by a second receiver; therefore, the two beams of optical pulse introduced into the balanced detector have the similar noise characteristic, so as to be beneficial to eliminating background noise. Furthermore, the first phase compensator is regulated to lead one path of light to work at the position with the best optical modulation degree, and the second phase compensator is regulated to lead the static birefringence phase values of the two paths of light to be opposite numbers, so that thelinear working range is not affected by static birefringence phase, and the signal to noise ratio can be optimized.

Description

technical field [0001] The invention belongs to the field of terahertz optics, and relates to an electro-optic sampling device and a measurement method for measuring terahertz optical pulses. Background technique [0002] Terahertz (THz) light refers to light waves with a frequency between 0.1 THz and 10 THz, and its wave band is between microwave and infrared. Terahertz light can penetrate various organisms, dielectric materials and gas phase substances. These media have rich absorption and dispersion characteristics in the terahertz band. By measuring and analyzing the terahertz signal of the sample, we can obtain information about the material composition and Physical, chemical and biological information. In terahertz optical technology, terahertz time-domain spectroscopy technology is one of the more important and commonly used technologies; there are two common terahertz measurement methods: light-guide opening method and electro-optical sampling method; among them, te...

AI Technical Summary

Problems solved by technology

This design has poor ability to cancel background noise

In addition, the linear dynamic range of the nearly 0° optical offset structure is narrow, and the overall performance is worse than that of the 45° optical offset structure, so it is rarely used by people.

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