Abstract

The early history of the double-Gauss design is that of dramatic performance improvement due to increased thickness of the inner glass shells. Generally speaking, many designs benefit from some very thick elements, which help correct astigmatism and reduce higher-order aperture aberrations. Such thick elements may not be practical to build unless the system focal length is quite short. Scan lenses and video disk read-out heads are examples where increased length and element thickness can have big performance payoffs. Chromatic variation in aberrations can also be reduced by this approach. Somewhat surprisingly, the long glass path is not easily eliminated by simply splitting elements or adding additional new ones. This trick, in some thick elements, becomes especially powerful when combined with a long total length for the design.

© 1989 Optical Society of America