QUANTITATIVE MEASURING METHOD FOR STABILITY OF CRYSTAL USED FOR OPTICAL ELEMENT EXPOSED TO HIGH ENERGY DENSITY, CRYSTAL GRADED BY THE METHOD, METHOD OF USING THE CRYSTAL

摘要

PROBLEM TO BE SOLVED: To quantitatively measure suitability of an optical material used for an optical element exposed to high energy density of a pulse laser, in particular, having 250nm or less of wavelength, especially an alkali metal halide single crystal and an alkaline earth metal halide single crystal.;SOLUTION: Radiation light-dependent transmissivity of the optical material is determined in an ultraviolet wavelength range by measuring fluorescence induced by ultraviolet radiation in the ultraviolet wavelength range. In the determination, the maximum induced fluorescence value in a nonlinear absorption process is determined, an inclination value |dT/dH| is determined as a functional relation indicating a dependence relation of the radiation light-dependent transmissivity with respect to action force H as to the induced fluorescence, and the radiation light-dependent transmissivity is determined as to a specified action force value, based on the inclination value.;COPYRIGHT: (C)2005,JPO&NCIPI