High-Power Laser Beam Coupler Using a Phase Diffraction Grating

Abstract

An increase in the radiation intensity of laser systems has dramatically complicated the control of the main parameters of the generated light beams. Measurements of the radiation power with total absorption calorimeters allow one to use these devices in a wide range of energies and wavelengths. However, such devices are not transmission-type gauges and, hence, exclude the simultaneous or subsequent use of the laser beam for purposes of the experiment [1, 2]. At a high-power density in the beam the probability of failure of the devices is high. Thus, for spherical calorimeters the fraction of absorbed energy is governed by the size of the input aperture. Even at a relatively small diameter of the optical beam, either the calorimeter dimensions become too large or the beam focusing is required. Although scanning calorimeters are transmission-type devices, thermal deformations of the POE distort the spatial characteristics of the beam. When measuring the divergence of the radiation of high-power laser facilities, the energy density in the focal region of the beam is critically close to the optical breakdown threshold. Therefore, the search for the ways of deflecting and attenuating radiation, while retaining its spectral characteristics, is still urgent.