HOLOGRAPHIC DEVICE FOR CONTROLLING SHAPE OF LARGE-SIZE CONCAVE ASPHERICAL OPTICAL SURFACES Russian patent published in 2022 - IPC G01B11/30 G02B5/32 

FIELD: optics.

SUBSTANCE: invention relates to production of large-size and high-aperture optical elements and components, mainly for telescopic systems for various purposes, namely to metrological support of processes of shaping large-size aspherical optical surfaces with high steepness and gradient of asphericity of concave mirrors of telescopes and can be used at all stages of their production and certification. Claimed holographic device for controlling the shape of large-sized concave aspherical optical surfaces comprises a laser light source, a first beam splitter for dividing light beams into a measurement and a reference channel, a second beam splitter for aligning light beams of the measurement and reference channels and directing them into the image recording and processing channel. Reference channel comprises a light beam expander, and the measuring channel comprises a monochromatic point light source, axial synthesized holographic optical element with a working surface of rotation, on which a coaxial annular diffraction structure is applied, and a collimating lens. In the measuring channel, a point diaphragm is introduced, which is installed with the possibility of placing the vertex of the controlled optical surface in its centre, and a diaphragm with a variable light diameter, located in the focal plane of the collimating lens, wherein the working surface of the axial synthesized holographic optical element is made in the form of a circular cone with its vertex facing the monochromatic point light source. Axial synthesized holographic optical element is installed with the possibility of forming, together with the controlled optical surface, an image of a monochromatic point light source in the plane of the diaphragm with a variable light diameter.

EFFECT: providing shape control of large-sized concave aspherical optical surfaces with high steepness and gradient of asphericity by reducing the dimensions of the axial synthesized holographic optical element as a result of using a diffraction structure made on the conical working surface of the substrate, providing compensation of longitudinal spherical aberration of light beams reflected from controlled optical surface, when obtaining a congruence of diffracted light beams with high non-homocentricity at a large angular aperture.

1 cl, 3 dwg