title: Effects of axial and radial gradients on Cooke triplets.
abstract: This study investigates the role of gradient-index materials in the design of Cooke triplets for use as 35-mm format photographic objectives. Cooke triplet designs are presented with different types of gradient-index profiles. Both linear axial and shallow radial gradients are shown to provide effective control of spherical aberration and astigmatism. In particular, a Cooke triplet with a combination of both linear axial and radial gradients attains performance comparable to a six-element double Gauss lens. In virtually all cases, the use of gradient-index components improves the Cooke triplets' performance significantly.
authors.forename: C G
authors.initials: CG
authors.lastname: Blough
authors.forename: J P
authors.initials: JP
authors.lastname: Bowen
authors.forename: N
authors.initials: N
authors.lastname: Haun
authors.forename: D S
authors.initials: DS
authors.lastname: Kindred
authors.forename: R J
authors.initials: RJ
authors.lastname: Koshel
authors.forename: D M
authors.initials: DM
authors.lastname: Krill
authors.forename: D T
authors.initials: DT
authors.lastname: Moore
authors.forename: C E
authors.initials: CE
authors.lastname: Saxer
authors.forename: D Y
authors.initials: DY
authors.lastname: Wang