Terahertz time-domain spectroscopy

Typical pulse as measured with THz-TDS.

In physics, terahertz time-domain spectroscopy (THz-TDS) is a spectroscopic technique in which the properties of matter are probed with short pulses of terahertz radiation. The generation and detection scheme is sensitive to the sample's effect on both the amplitude and the phase of the terahertz radiation.

Fourier transform of the above pulse.