Transmissivity Testing Of Calcium Fluoride Windows Under High Pulse Repetition Rate Laser Irradiation At 193nm

It is hard to judge quality of CaF2 window from its nominal specification, because suppliers are used to testing products performance under relatively weak spectral lines from lamp, which can not tell the real operation behavior of CaF2 window under intense laser irradiation. We report a method of testing the transmissivity of three different grade commercially available CaF2 windows under high pulse repetition rate laser irradiation at 193nm, and the lab prototype of test module distinguishes them well with a repeatability better than 2%.