YTTRIUM OXIDE COATED OPTICAL ELEMENTS WITH IMPROVED MID-INFRARED PERFORMANCE

摘要

The disclosure is directed to a method of making yttrium oxide, Y2O3, coatings on substrates suitable for use at infrared wavelengths, including use in the 2-12 mum range. The coating method eliminates or substantially eliminates the absorptions peaks that typically appear at approximately 3.0 mum, 6.6 mum and 7.1 mum. This is achieved by using Y metal as the yttrium source in combination with an oxygen-containing plasma to form the Y2O3, coating in place of the using Y2O3 as the coating material source The disclosure is further directed to optics suitable for use in the infrared that have such coatings. The transmission spectrum of the coated substrate made according to the method described herein is greater than the transmission spectrum of the uncoated substrate over the wavelength range of 4 mum to 12 mum.