Terahertz time-domain spectrograph capable of entering at fixed angle and simultaneously detecting transmission and reflection

Abstract

The invention discloses a terahertz time-domain spectrograph capable of entering at a fixed angle and simultaneously detecting transmission and reflection and belongs to the technical field of spectrums. The spectrograph is characterized in that a femtosecond laser device is used as an excitation source, and a beam splitter arranged at the output end of the femtosecond laser device is used for splitting one beam of laser into two beams, wherein one beam is detection light; the other beam is further split into two beams through a beam splitting prism, wherein one beam is used as pumping light and the other beam is also used as the detection light; the pumping light is gathered on a terahertz transmitter and pulse terahertz waves are generated by radiation; the generated terahertz waves are used for irradiating a sample; the terahertz waves transmitting the sample are focused on one path of terahertz detector, and the terahertz waves reflected by the sample are focused on the other path of terahertz detector; the two paths of detection light are also focused on the two terahertz detectors at the same time, and pulse terahertz wave electric field amplitude values of transmission and reflection are calibrated. In the system, a relative position between a reflecting mirror and the sample is fixed, and a transmission spectrum and a reflection spectrum of the sample can be obtained at the same time, so that the transmittance and the reflectivity of the sample are accurately obtained, the reliability of data is guaranteed and experiment efficiency is also improved.

Description

technical field [0001] The invention relates to the technical field of spectroscopy, in particular to a terahertz time-domain spectrometer capable of simultaneously measuring transmission and reflection at a fixed angle of incidence. Background technique [0002] The frequency range of terahertz electromagnetic waves is generally defined as 0.1 THz to 10 THz. Terahertz technology has been applied in many fields. Terahertz time-domain spectroscopy technology is an important technology for the practical application of terahertz science. This technology has a high detection signal-to-noise ratio and a wide detection bandwidth, and can be widely used in material property analysis, biomedical research, and security detection. It has a very practical application prospect. [0003] Existing terahertz time-domain spectrometers adopt transmission or reflection structures, such as figure 1 , 2 . In the existing system, only one measurement mode can be selected at a time, either f...

AI Technical Summary

Problems solved by technology

In the existing system, only one measurement mode can be selected at a time, either for transmission measurement or reflection measurement, and the transmission spectrum and reflection spectrum cannot be obtained at the same time, so the transmission spectrum and reflection spectrum of the sample cannot be analyzed at the same time when processing data take measurements

Moreover, for the situation where both transmission information and reflection information are required, the test sample chamber needs to be replaced many times, and the operation is complicated and very inconvenient

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