title: Design of fast aplanatic IR objectives using high refractive-index materials.
abstract: A method for correcting spherical aberration and coma in fast two-element objectives using high-index materials is discussed. It involves use of an aplanatic lens with a single lens having a minimum spherical aberration and no coma. The method deals only with monochromatic designs. It can be effective in designing high-aperture aplanatic IR objectives. Optical data and performance characteristics of germanium and silicon two-lens systems designed by the proposed method are given.
authors.affiliation: Instruments Research & Development Establishment, Dehra Dun, India.
authors.forename: K O
authors.initials: KO
authors.lastname: Varughese
authors.forename: K K
authors.initials: KK
authors.lastname: Banerjee
authors.forename: R
authors.initials: R
authors.lastname: Hradaynath