Optical system for application of THz spectroscopy and THz imaging

Abstract

We have built up two sets of THz generation and detection system. One uses the photoconductor antenna as the THz emitter, which can generate a stronger THz electromagnetic radiation. Its spectral range is relative narrow 0.1 - 1.1 THz, so it is suitable to the application of THz imaging. Another uses a femto-second laser pulse to excite semiconductor surface and generates the broadband THz radiation with the spectral range between 0.2 THz and 3.0 THz, which is suitable for the study on THz time resolved spectroscopy. Both of the THz setups utilize the detection technology of free-space electro-optic sampling, and realize the experimental function of low noise, high sensitivity high signal-to-noise ratio and very large of dynamical range. The signal-to-noise ratio of our system achieve at above 600. The dynamical range is 10 4 . Therefore, our setup provides a strong experimental basis for THz spectroscopy and imaging, and is ready to study on the application of THz optics, THz chemistry, material science, biology and medicine.