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.
© 1990 Optical Society of America
C. Gary Blough, John P. Bowen, Niels Haun, Douglas S. Kindred, R. John Koshel, Daniel M. Krill, Duncan T. Moore, Christopher E. Saxer, and David Y. H. Wang, "Effects of axial and radial gradients on Cooke triplets," Appl. Opt. 29, 4008-4015 (1990)