CATADIOPTRIC SYSTEM Russian patent published in 2012 - IPC G02B17/08 

FIELD: physics.

SUBSTANCE: system includes two hyperbolic mirrors lying on a beam path, the first facing the object space with its concave side, and the second facing the first with its convex side. The first mirror has a centre hole with diameter D₁. D₁≤D₂, where D₂ is the clear aperture of the second mirror. Near the focal plane of the lens there is a lens corrector, all of the working surfaces of which are spherical and the clear aperture D₃ is such that D₃≤D₁. The first mirror has optical power φ1 such that -3.2≤φ1≤-3.0, with eccentricity squared ℮₁ ² such that 1.00≤℮₁ ²≤1.26. The second mirror has optical power φ2 such that -8.0≤φ2≤-7.0, with eccentricity squared ℮₂ ² such that 4.5≤℮₂ ²≤6.5. The distance d_1-2 between the first and second mirrors is such that 0.3f≤d_1-2≤-0.2f, where f is the focal length of the system. The corrector is in form of a meniscus lens whose convex surface faces the second mirror, with optical power φ3 such that -3.4≤φ3≤-2.8, and lies at a distance d_2-3 from the second mirror, which is such that 0.16f≤d_2-3≤0.3f. The thickness h of the meniscus of the corrector is such that 0.004f≤h≤0.006f.

EFFECT: obtaining a high-quality image in a wide spectral range, which is uniform on the field of view using standard manufacturing, assembling and adjustment techniques.

1 dwg, 5 tbl