X‐ray damage in optical coatings

Thin film coatings are susceptible to high intensity x‐ray damage. The PHAROS III laser was utilized to generate a point source of x‐ray emission used to determine the damage threshold of AR‐coated space optics. Thin filters coupled with magnets were used to shield the specimens from thermal radiation and plasma debris. Grids supporting the thin filters could be patterned into the coatings. The surface morphology of damaged specimens has been examined with SEM and AFM microscopes to determine the nature of the damage in multilayer AR coatings. Microscopic techniques were used to measure the depths of coating damage and edge sharpness in the patterned region.