LASER DAMAGE TEST BENCH FOR SPACE OPTICS

Abstract

At the German Aerospace Center in Stuttgart a laser damage test bench is run to evaluate damage thresholds of various optical components. The system setup is based on the current ISO standards 11254 for single shot and multiple pulse operation. The laser damage test bench contains two repetitively pulsed laser sources, a Ti:Sapphire and a Nd:YAG laser, operating at wavelengths of 775 nm and 1064 nm, respectively. Harmonic wavelength converters to the visible spectral range are available. Both lasers are supplying the same damage testing rig. Online damage assessment techniques like sensitive scatter probe monitoring and video microscopy monitoring are used. The system is suited and has been tested extensively in the past for dielectric coated optics like beam turning mirrors, reflectors and windows, nonlinear optical components, semiconductors, and laser crystals. The damage test bench is located in a class 10,000 cleanroom environment under a laminar flowbox providing an additional isolation factor of >10^3. The tests can also be performed in sealed optical compartments in partial vacuum and under long term irradiation conditions. All experiments are supported by theoretical simulation of laser-material interactions, down to the sub-ps timescale.