Fourier transform in THz measurements of refractive index

Abstract

A Fourier Transform is applied to the coherent detection signal in the THz photomixer arrangement. The method is used in measurements of a refractive index of plastic materials.

Selected polymers on CW and pulsed THz investigations

“…Continuous wave operation can be easily obtained with a terahertz photomixer -see Fig 1. It consists of two main optical arms: a pumping beam (a distance from a cubic beam splitter BS to a transmitting antenna Tx plus a tera− hertz part from Tx to a receiving antenna Rx), and a probing beam (a distance from a cubic beam splitter BS, via mirrors arrangement to a receiving antenna Rx) [9]. The signal trave− ling along the pumping arm excites carriers at the LT−GaAs photoconductive antenna.…”

All fiber THz spectrometer for plastics industry

“…It has been shown that the THz technology is applicable to a non-destructive inspection of industrial goods and plastics [1,2] as well as in the semiconductor industry, homeland security [3], biology and medicine. The polymer industry is of a special interest, while many polymers and additives are transparent to the THz waves.…”