METHOD FOR INCREASING LASER INDUCED DAMAGE THRESHOLD BY ETCHING OF OPTICAL SUBSTRATES

摘要

This invention provides a simple and rapid method for enhancing the surfaces of optical substrates by removing the polished layer and cleaning out the slurry containing subsurface damage. The method comprises the following steps: preparation of the polished optical glass sample (5) by cleaning in an ultrasonic bath, preferably containing potash as the cleaning fluid; placing and soaking the cleaned sample (5) in an etching mixture of hydrogen fluoride and nitric acid (6); hermetically securing the non-etched sample surfaces in the etching environment; soaking the sample for a predetermined time interval; removing and rinsing the sample with an appropriate washing fluid. During the etching procedure the humidity and temperature of the etching environment is controlled. The sample during the etching procedure is placed in the etching environment in such a way that the surface being etched is as level as possible.