Calcium fluoride optical member, method for producing calcium fluoride member, and method for processing calcium fluoride single crystal

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a CaFmember in which CaFmembers of various shapes can be easily obtained.SOLUTION: A manufacturing method of a calcium fluoride member includes heating a calcium fluoride single crystal higher than 250°C and applying pressure to the heated calcium fluoride single crystal to implement plastic deformation. For example, a hollow cylinder C is formed by shaving processing from an ingot of a CaFsingle crystal ingot, and its inside is filled with high pressure gas G and sealed. By means of this, the inner wall receives the pressure from the gas G and is being pressurized to the direction of the radial direction outside at all times. Under such a condition, the hollow cylinder C is made to be able to plastically-deform by heating through that a heater 51 heats locally the central part Co of the hollow cylinder C, and the central part Co of the hollow cylinder C is inflated outside, to form a spherical shell part 1s.