Antireflecting Film Development. Final Report

摘要

A metal-organic precursor was formulated that is converted by heating on surfaces of ordinary glass to a phase-separated metal-organic-derived glass coating, without exceeding 375 exp 0 C. This phase-separated layer is quickly and easily leached by nitric acid to leave a graded index, antireflective coating on ordinary glass (e.g., BK-7 optical glass or fused silica) that protects it against damage by high fluence of laser light at 1060 nm and shorter wavelengths. The metal-organic precursor is relatively inexpensive, and the thickness applied to the glass surface is not very critical for the achievement of protection for the glass surface from 1 ns pulses of laser energy. Laser damage testing at 248 nm with this coating on silica discs was thought to show separation of the coating from the substrate at fluences as low as 1.2 J/cm exp 2 with fracture damage at 4.9 J/cm exp 2 . These tests results provide a criterion we lacked. If laser damage tests could be performed promptly, we recommend treatments that should strengthen the union of coating to substrate. (ERA citation 06:033563)