APOCHROMAT LENS Russian patent published in 2022 - IPC G02B9/34 

FIELD: telescopic systems.

SUBSTANCE: invention can be used as a lens for telescopic systems for various purposes. The apochromat objective includes two two-lens components separated by an air gap d₂, the first component contains biconvex and biconcave lenses arranged sequentially along the beam, separated by an air gap d₁, the lenses of the second component are separated by an air gap d₃. The second component consists of a plano-convex lens in series along the beam and a negative meniscus with its convex surface facing the plano-convex lens. The air gap d₂ satisfies the condition d₂≤D, where D is the diameter of the entrance pupil of the lens. The first and third lenses are made of glass that meets the conditions: 1.49≤n_d≤1.53 and 80≤ν_d≤85, and the second and fourth lenses are made of glass that meets the conditions: 1.55≤n_d≤1.57 and 60≤ν_d≤65, where n_d is the refractive index for the d line, ν_d is the Abbe number.

EFFECT: simplification of the design, increase in the working spectral range and increase in the field of view while maintaining the luminosity and a high degree of correction of geometric and chromatic aberrations of the device.

1 cl, 4 dwg, 1 tbl