Full electro-optic terahertz time-domain spectrometer for polarimetric studies

We present a terahertz (THz) time-domain spectrometer dedicated to polarimetric studies. THz pulses are generated through optical rectification in a ⟨111⟩-cut cubic crystal. The ⟨111⟩ crystal cut produces a THz polarization state similar to that of the exciting laser beam. Detection of the THz pulses is performed by electro-optic sampling in a similar crystal, and a dual detection scheme allows us to measure simultaneously the two polarization components of the THz beam. We experimentally illustrate that the polarization of the THz beam can be adjusted by adjusting the laser polarization. This technique alleviates the need for a polarization controller at THz frequencies.