Laser damage evaluation method of optical material

摘要

PROBLEM TO BE SOLVED: To provide a laser damage evaluation method of an optical material capable of nondestructively and inexpensively evaluating laser damage of an optical material in a short time without contacting it.;SOLUTION: In relation to a pulse laser beam and an optical material wherein, when variation of the transmittance of the optical material is investigated while increasing light incident energy, the material shows behavior where the transmittance is decreased by linear absorption and thereafter nonlinearly decreased; when the light incident energy is further increased, a phenomenon resulted in destruction occurs, and the behavior nonlinearly decreasing the transmittance is changed in accordance with crystalline quality of the optical material; and it is determined that the nonlinear transmission decrease is caused by absorption of two photons; incident laser beam intensity and transmitted laser beam intensity are measured by changing incident pulse laser beam intensity, and incident light intensity and transmitted laser beam intensity obtained by changing incident pulse laser intensity in a plurality of crystalline materials of the same kind having a previously-obtained laser damage threshold value are compared with the results obtained by measurement to nondestructively evaluate laser damage resistance accompanying laser beam irradiation.;COPYRIGHT: (C)2009,JPO&INPIT