Patent ID: 6782075
Filing Date: 2004-08-24
Classification: G01N,G02B,G03F

Abstract:
A method of making a below 200 nm wavelength fluoride crystal optical element, said method comprising:providing a fluoride single crystal, irradiating at least one volume element of the fluoride single crystal, along at least one family of crystalline planes with a hard x-ray beam, in order to obtain a picture of the diffraction in transmission mode of the hard x-rays across this at least one volume element along this at least one family of crystalline planes, studying the picture of the diffraction in transmission mode and calculating a mosaicity of the at least one volume element along the at least one family of crystalline planes to provide a selected optical fluoride crystal having a determined mosaicity of less than 10â€² across the at least one volume element, forming said selected optical fluoride crystal having a determined mosaicity of less than 10â€² across the at least one volume element into a below 200 nm wavelength fluoride crystal optical element having a mosaicity of less than 10â€².