Patent ID: 9007565
Filing Date: 2015-04-14
Classification: G02B,G03F

Abstract:
1. A spectral purity filter, comprising: a body of material, through which a plurality of apertures extend; the apertures being arranged to suppress radiation having a first wavelength and to allow at least a portion of radiation having a second wavelength to be transmitted through the apertures, the second wavelength of radiation being shorter than the first wavelength of radiation; the body of material being formed from a tungsten-molybdenum alloy or a molybdenum-rhenium alloy or a tungsten-rhenium alloy or a tungsten-molybdenum-rhenium alloy, wherein the body of material further comprises a plurality of nanoparticles for increasing a re-crystallization temperature of the body of material as a whole, and wherein the nanoparticles comprise of one or more of: Al