Laser Stand for Measuring the Radiation Resistance of Optical Elements at a Wavelength of 2. 87 m

This paper reports on the development of a laser stand based on a Cr: Yb: Ho: YSGG laser (=2. 87 m) with a pulse energy of 15 mJ and a pulse duration of 40 ns, operating in Q-switched mode. The stand is designed for measuring the radiation resistance of optical elements used at the wavelength range of 3 m and for other experiments on the interaction of radiation with matter. The features of measuring the laser radiation caustics near the focal plane of a lens with f=50 mm using the scanning knife-edge method with different temporal structures of the radiation pulse are discussed. The energy density on the surface of the optical element under study with a laser spot diameter of 160 m can be smoothly varied within the range of 1-52 J cm ^-2