Two-Frequency THz Spectroscopy for Analytical and Dynamical Research

Development of high-sensitivity and high resolution analytical spectroscopy is an area of active research interest currently. In the paper a method of two-frequency THz spectroscopy is presented. A laboratory model of spectrometer using two independent radiation sources of 118-178 GHz and 330-390 GHz ranges and a single detector with 500-2500 V/W sensitivity is presented. Test measurements allowed detecting two gases simultaneously with the minimal registration period of 4 μs and the hardware resolution of 1 kHz. These experiments proved this new trend in analytical spectroscopy to have wide application prospects for a variety of fundamental and applied scientific problems. In the first place, it is laboratory modeling of the processes of atmospheric and space chemistry, studying of their dynamics as well as transformations and changes of mixture composition. Besides, the proposed method can be applied to investigations of fast processes, detection of intermediate and short-lived products of chemical reactions.