Frequency-selective surfaces analyzed by THz-time-domain spectroscopy

The transmission and phase shift characteristics of dichroic high-pass and cross-shaped grid bandpass filters were measured in the region from 0.1 to 1.5 THz with an electro-optic (eo) sampling THz-time-domain spectrometer. Good agreement with applied transmission theories is found. In this spectral region, which is difficult to access by conventional means, the knowledge of the frequency response of these frequency-selective surfaces (FSS) is important for applications in frequency mixing and multiplying experiments. Alternatively, FSS's permit temporal shaping of THz pulses for frequency selective ultrafast experiments in the THz range.