METHOD OF MAKING HOLLOW BILLET FOR MIRROR ELEMENT FOR OPTICAL SYSTEMS Russian patent published in 2016 - IPC G02B5/08 C23C14/34 

FIELD: optics.

SUBSTANCE: invention relates to production of light-reflecting elements of irregular shape and can be used for producing high-precision light-reflecting optical elements of astronomical mirrors. According to invention, method includes forming on surface of irregularly shaped articles a bearing metal-coated layer of galvanic nickel-cobalt coating with content of cobalt in precipitate of 15-20 %, from sulphamine electrolyte at current density 2.5-3.0 A/dm², temperature 55-60 °C. Produced replica is removed by thermal shock and light-reflecting layer is applied iridium by high-precision cathode sputtering on internal surface of nickel-cobalt replica to form a thin-walled light-reflecting element for subsequent installation into an optical system.

EFFECT: technical result is reduction of thickness and internal stresses of base layer billet due to increased strength of workpiece, improved contrast spot and reducing deformation distortion of images obtained using ready optical mirror.

1 cl, 1 tbl, 1 ex