1.5 Port Vector Spectrometer for Terahertz Time Domain Spectroscopy

We demonstrate a spectrometer capable of measuring terahertz time domain transmission and reflection spectroscopy simultaneously in a single setup. This facilitates highly accurate determination of optical material parameters and the geometric thickness by taking advantage of both geometries. The system is also suitable for parameter extraction for materials when data from transmission geometry cannot be extracted and for characterizing non-time-invariant devices such as optical isolators.