METHOD FOR GENERATING NARROW-BAND TERAHERTZ RADIATION (EMBODIMENTS)

摘要

FIELD: optics.;SUBSTANCE: invention relates to optics and to a method for generating narrow-band terahertz radiation. Generation is carried out by action of linearly polarized femtosecond laser pulses on the input surface of an anisotropic nonlinear single crystal, which leads to transformation of radiation with a terahertz output in the direction of propagation of laser pulses at the length of the passage of these pulses in a single crystal equal to the absorption length of terahertz radiation at the operating frequency in it, and the terahertz output in the opposite direction, at the length of the passage exceeding the absorption length of terahertz radiation at the operating frequency. For optical rectification of laser pulses due to nonlinear mixing of spectral components of ordinary and extraordinary waves formed after refraction of a laser beam on the input surface of a single crystal, under conditions of formation of induced nonlinear polarization with a variable polarity in it, the single crystal is oriented with crystallographic axis [100] or [010] lying in the plane of its input surface, to forma an angle with the direction of the polarization vector of the exciting beam, which ensures formation of ordinary and extraordinary waves.;EFFECT: technical result consists in narrowing the width of the line of the generated radiation.;4 cl, 5 dwg