ИСТИНА

Despite the eff ective development of THz range, high spectral brightness radiation sources are still not readily available. One method of generating THz radiation is to use a crystal with a high nonlinear optical coeffi cient to convert an intense laser pulse into THz range. The creation of eff ective terahertz radiation generators depends heavily on the search for and research of new nonlinear optical crystals (or other materials). In this regard, the paper presents studies of the optical properties of a new monoclinic semi-organic crystal of guanylurea hydrogen phosphate — GUHP, promising for effi cient optical-terahertz conversion. [1]. An optical bench has been developed — a polarizing THz spectrometer, based on a continuous tunable source. Broadband polarizers built on an aluminum grating printed on a thin polypropylene substrate are utilized. The characteristics of the installation based on the Terahertz Frequency domain spectrometer (THz-FDS) Toptica Terascan were studied and its calibration was carried out. The angle of rotation of the main optical axes of the crystals relative to the crystallographic ones was measured. The dispersion of the refractive index and absorption coefficient from 0.2 to 2.2 THz was measured on a Terahertz Time domain spectrometer (THz-TDS). The optical properties are measured with great accuracy in the vicinity of 1.5 THz, in which eff ective generation of THz radiation under laser pumping is demonstrated, and the x axis absorption peaks in the vicinity of 1.45 and 1.85 THz (Fig. 1) are defined for the fi rst time.