The traditional approach to design of baffles for suppressing stray radiation uses a tube lined with black diffuse baffles to eliminate single-scatter paths to the primary optics. However, the black baffles can absorb an excessive amount of heat and contribute to increased background radiation at infrared wavelengths if used in proximity to relatively intense off-axis radiation sources, such as the sun in some sensor applications or the earth itself in other applications. This paper describes a baffle tube design using reflective baffles of elliptical cross section. The design rejects most of the load, but intrinsic limitations allow some skew rays to land on surfaces facing the primary, resulting in increased scatter. The benefits of decreased aperture load must be carefully weighed against increases in background due to scatter. Fabrication tolerances must also be considered, because they will degrade performance. This paper addresses these tradeoffs and describes some analysis methods for evaluating specular baffle designs.

Date Published: 27 May 1982
PDF: 8 pages
Proc. SPIE 0330, Optical Systems Engineering II, (27 May 1982); doi: 10.1117/12.934257

Published in SPIE Proceedings Vol. 0330:
Optical Systems Engineering II
Paul R. Yoder Jr., Editor(s)