Diffractive optical elements (DOEs) are more flexible and powerful than tradition refractive-reflective optical elements in correcting chromatic aberration of an optical system. In this paper the principle of correcting secondary spectrum is described. In order to compare the effect of DOEs on correcting secondary spectrum, we use CODE V to design a refractive telephoto system with different strategies: (I) All surfaces are spherical; (II) One surface is diffractive in the system; (III) Two or more surfaces are diffractive (Multi-layer diffractive system). It is found that multi-layer diffractive elements used in a telephoto system can easily correct secondary spectrum without high dispersion glasses, such as calcium fluoride, at the same time high diffraction efficiency and broad spectral bandwidth can be obtained. And the most important of all, the length of the telephoto system can be shortened by about 30%, and the weight can be greatly cut.

Date Published: 12 March 2008
PDF: 7 pages
Proc. SPIE 6624, International Symposium on Photoelectronic Detection and Imaging 2007: Optoelectronic System Design, Manufacturing, and Testing, 66240W (12 March 2008); doi: 10.1117/12.791096

Published in SPIE Proceedings Vol. 6624:
International Symposium on Photoelectronic Detection and Imaging 2007: Optoelectronic System Design, Manufacturing, and Testing
Liwei Zhou, Editor(s)