REFERENCE DIFFRACTIVE OPTICAL ELEMENT (VERSIONS) Russian patent published in 2014 - IPC G02B5/18 G02B27/44 

FIELD: physics.

SUBSTANCE: invention can be used in making high-precision diffractive optical elements, such as wave front (aberration) correctors and reference diffractive lenses for controlling quality of optical surfaces using an interferometric technique. A diffractive optical element consists of a wedge-like plate with a surface layer having a diffraction structure in the form of a set of zones. In the first version, the surface layer in the form of one or two stacked thin optical films with different refraction indices and/or absorption coefficients. Zones of the diffraction structure lie on the outer film relative to the plate. The relief depth h of the zones of the diffraction structure is defined by a formula given in the claim. In the second version, zones of the diffraction structure diffusively reflect and/or scatter optical radiation. The third version further includes an antireflection layer between the diffraction structure and the surface of the plate, and zones of the diffraction structure made of metal.

EFFECT: high measurement accuracy, larger clear aperture of the measurement wave front, enabling formation of spherical and aspherical wave fronts, simple design, reduced weight and size and broader functional capabilities.

6 cl, 9 dwg, 2 tbl