Abstract

Terahertz time-domain spectroscopy with the detection of the electric field waveform of the pulses have been widely spread as a highly versatile method in these decades. By using ultrashort optical pulses with the pulse width of approximately 10 fs, the frequency range can be extended to the multi-terahertz frequency region, i.e. frequency of several tens of THz (10-50 THz in frequency, 6-30 μm in wavelength). The broadband spectrum is highly beneficial to measure the complex response function of materials and its ultrafast dynamics in the pump-probe scheme [1]. In general, however, the response function is a tensor quantity. To obtain the off-diagonal components for studies such as vibration circle dichroism or anomalous Hall conductivity, multi-terahertz polarization-resolved measurement is required. Due to the limitations of bandwidth and dispersion of the polarization elements available in this frequency, however, the waveform can be severely distorted, which makes the polarization-resolved multi-terahertz spectroscopy difficult.

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