OPTICAL REFLECTING THIN-FILM COATINGS

摘要

Optical coatings comprising layers of low index materials alternating with layers of high index materials where a plurality of the high index layers resistant to high temperature and/or UV have essentially stable electrical resistivity properties when subjected to ultraviolet portions of the electromagnetic spectrum and/or high temperatures are taught. These coatings are well-suited for today's small high intensity lamps and reflectors used in higher performance projection and lighting systems. These high index materials are chosen to have an index of refraction equal to or greater than 1.8 and a melting temperature greater than 500 °C and may be, for example, selected from the group consisting essentially Of Ta<SUB>2</SUB>O<SUB>5</SUB> Or Nb<SUB>2</SUB>O<SUB>5</SUB>, HfO<SUB>2</SUB>, ZrO<SUB>2</SUB>, WO<SUB>2</SUB>, Mo<SUB>2</SUB>, In<SUB>2</SUB>O<SUB>3</SUB> or blends thereof. Coatings selectively reflect desired wavelengths, e.g., one coating reflects at least 95 % of visible light and transmits at least 80 % of infrared.