A passion for terahertz optoelectronics

THz time-domain spectroscopy is a direct extension of ultrafast optoelectronics. The major components of THz time-domain spectroscopy include a laser, a THz emitter and detector, focusing and collimating components for both the laser and the THz optics, samples, a chopper, a motorized delay line, a lock-in amplifier, and a data acquisition system. The femtosecond laser pulses are divided into pump pulses used to generate single-cycle 1-ps bursts of THz radiation The THz pulses and probe pulses arrive simultaneously at an electro-optic sampling detection system, consisting of an EO crystal, a quarter waveplate, a Wallaston prism, and a pair of balanced photodiodes.