Blough C G, Bowen J P, Haun N, Kindred D S, Koshel R J, Krill D M, Moore D T, Saxer C E, Wang D Y
Appl Opt. 1990 Oct 1;29(28):4008-15. doi: 10.1364/AO.29.004008.
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.
