Spectroscopic imaging by two-dimensional electrooptic sampling in the terahertz region

A terahertz (THz) time-domain imaging system is developed based on two-dimensional electrooptic sampling with a high-speed complementary metal-oxide semiconductor camera. Spectroscopic images are observed under nondestructive and noncontact conditions to demonstrate transmissive imaging of an L-cystine chip embedded in a polyethylene pellet. Time waveforms that have a time period of 68.1 ps are acquired for 16384 pixels within six minutes during the observation. The L-cystine chip, which has a fingerprint spectrum in the THz region, is depicted clearly in the spectroscopic image at the fingerprint frequency by reassembling the image from the spectrum obtained by Fourier transform of th…