METHOD OF PRODUCING MENISCUS FROM LITHIUM FLUORIDE CRYSTALS Russian patent published in 2020 - IPC B29D11/00 C30B33/02 C30B29/12 G02B1/02 G02B3/00 

FIELD: optics.

SUBSTANCE: invention relates to the technology of obtaining meniscus, shells and lens workpieces of optical systems of modern optical, optoelectronic and laser devices operating in the ultraviolet, visible and infrared regions of spectra, and can be used to produce convex-concave lenses from lithium fluoride crystals. Method consists in making workpieces by plastic deformation of discs of lithium fluoride crystals, cut from plates, perpendicular to crystallographic axes of 3rd or 4th order, wherein plastic deformation is carried out in a vacuum with a hemispherical puncheon with radius R_p in isothermal conditions at temperature of 680–710 °C with constant speed of 2–5 mm/s in matrix with working surface radius R=(R_p+r_m) sin β, where R_p is the puncheon radius, r_m is radius of matrix arm, and β – central angle is half the angular aperture of the workpiece, to the deflection h≤(1-cos β)⋅(R_p+ r_m), then cooled to temperature of 400 °C at a rate of not more than 5 °C/min.

EFFECT: obtaining meniscus from high-optical-quality lithium fluoride crystals.

1 cl, 2 ex