Detection of the THz waves from the 5m distance

Abstract

We report on technical aspects connected with detection of the terahertz (THz) waves reflected from a small target which is situated at the distance of 5 meters. Details of experimental setup are presented. An optical parametric oscillator (OPO) was used as a THz nanosecond pulses radiation source and a hot-electron bolometer (HEB) was applied for pulse detection. A method of spectrum calculation from experimental data is described. Measured reflectance spectra of few materials are presented with explanation of the origin of water vapor hole burning in the reflectance spectrum.