Automatically successive waveform acquisition with THz-TDS in a wide frequency range

We developed a THz time-domain spectroscopic system including two kinds of THz-emitter, i.e., a low -temperature-grown GaAs (LT-GaAs) photoconductive switching substrate and 4- dimethylamino-N-methyl- 4-stibazolium tosylate (DAST) crystal with the laser pulses of 780 nm and 1560 nm, respectively. Two kinds of THz-emitter can be automatically exchanged one another for a femtosecond pulse laser and a detector, in order to acquire the THz spectra successively under the environment without water vapor. The spectral acquisition with two emitters in the range between 0.04 and 7.0 THz can be obtained for seven samples in sequence. The system overcomes the disadvantage that THz-TDS covers relatively limited frequency range with an emitter and is easy-to-use even for the researchers inexperienced for THz-TDS.