Abstract

Close to spherical and different smooth flat-top shape surfaces, which are SiO₂, SiO or MgF₂ single profiled films with ~0.5-2-μm maximum thickness, were deposited on glass or quartz substrates by electron beam, resistive heating or sputtering techniques. The comparative analysis of rotating mask and noncontacting (fixed) mask methods (the use of shadow effect of the mask on substrate) for preparation of profiled films has been carried out. The advantage of using sputtering units with a large source for preparing flat-top profiled films is discussed. The possibilities of using chemical etching with laser heating for this purpose are examined experimentally. Such profiled film was used in a frustrated total internal reflection amplitude filter; there it separated the hypotenuse faces of two right-angle glass prisms. Results are presented of testing such filters in lasers and laser radiation damage thresholds of different films in optical contact conditions. A comparison of laser damage thresholds of nonconducting films and in optical contact conditions is given.

© 1991 Optical Society of America