Time-domain characterization of electric field vector in multi-terahertz pulses using polarization-modulated electro-optic sampling.

We demonstrated characterizing the electric field waveform of multi-terahertz pulses (10 - 50 THz) as vector quantities in the time domain by applying the polarization modulated electro-optic sampling (POMEOS) method. The problem of an ultrabroadband gate pulse was solved by modifying the fitting function in POMEOS, and its validity was confirmed through numerical simulations. High accuracy and precision of approximately 1 mrad with 3 s accumulation were demonstrated.

Jitter correction for asynchronous optical sampling terahertz spectroscopy using free-running pulsed lasers.

We demonstrate a jitter correction method for asynchronous optical sampling (ASOPS) terahertz (THz) time-domain spectroscopy using two free-running oscillators. This method simultaneously records the THz waveform and a harmonic of the laser repetition rate difference, , to monitor the jitter information for software jitter correction. By suppressing the residual jitter below 0.

Polarization-sensitive terahertz time-domain spectroscopy system without mechanical moving parts.

We report on the measurement of terahertz electric-field vector waveforms by using a system that contains no mechanical moving parts. It is known that two phase-locked femtosecond lasers with different repetition rates can be used to perform time-domain spectroscopy without using a mechanical delay stage. Furthermore, an electro-optic modulator can be used to perform polarization measurements without rotating any polarizers or waveplates.