Verfahren zum Herstellen einer orientierten Vorform aus einem Fluoridkristall

摘要

A method of making an oriented fluoride crystal blank for transmitting below 250 nm ultraviolet light includes irradiating a fluoride crystal blank with an x-ray beam, detecting the x-ray beams diffracted from the fluoride crystal blank, generating a diffraction pattern from the x-ray beam diffracted from the fluoride crystal blank, determining an angular deviation of an optical axis of the fluoride crystal blank from a specific crystallographic direction, and, if the angular deviation is not within a predefined range, modifying the fluoride crystal blank in a manner such that that the resultant angular deviation between the optical axis of the fluoride crystal blank from the specific crystallographic direction after modifying falls within the predefined range.