FAST CATADIOPTRIC OBJECTIVE Russian patent published in 1997 - IPC

FIELD: optical engineering. SUBSTANCE: fast catadioptric objective has first positive flat-convex lens, second surface of which is provided with mirror reflecting coating in central part, and negative meniscus lens facing the object with its concave section. Lenses are installed in direction of travel of rays. Second surface of meniscus lens has circular reflecting coating and aberration compensator positioned in joining bundle of rays near image surface and made as positive component. Aberration compensator in joining bundle of rays is also provided with second positive lens. Both lenses are single positive menisci, first of which facing the object plane with its convexity and second facing the image plane. Optical force of aberration compensator is determined by condition: Φ_c = ( 1,1 ÷ 1,5) Φ_ob. In this case, dispersion of material of first positive lens, negative meniscus and first lens of aberration compensator is the same and is selected from condition: 55,0 ≅ ν_d ≅ 70,0. Dispersion of second lens of aberration compensator is found from condition; 30,0 ≅ ν_d ≅ 45,0, where Φ_c is optical force of aberration compensator; ν_d is objective optical force, and Φ_ob is dispersion of lens material. EFFECT: improved design of objective. 1 dwg, 4 tbl