MIRROR ATHERMALIZED LENS Russian patent published in 2019 - IPC G02B17/08 

FIELD: optics; electrical equipment.

SUBSTANCE: lens can be used in opto-electronic systems and when a high level of heat resistance is needed. Lens contains a meniscus installed along the beam, facing the concavity of the space of objects, Mangein's lens in the form of a concave meniscus with a hole in the central zone facing with concavity to the space of objects, a secondary convex mirror that convexly faces the image space, a two-lens compensator, the first lens of which is negative convex-bent and the second negative. Equivalent compensator focal distance – (0.15–0.20)f', where f' – focal length of the lens. All optical elements are made of one optical material with a dispersion coefficient of 60≤ν_d≤70 and temperature coefficient of linear expansion of 0.2×10^-6≤α_t≤8.5×10^-6 °C^-1, which differs from the temperature coefficient of linear expansion of the material from which the mechanical parts of the lens are made, by no more than 1.5×10^-6 °C^-1.

EFFECT: production of a long-focus lens, athermalized in the range of -40 °C to +50 °C, with high image quality in a wide spectral range across the entire field of view and preserving sealing with significant temperature differences, simplifying the design and reducing the size and weight.

1 cl, 3 dwg, 2 tbl