Innovative software simulation techniques to design specular curved baffle designs in ground- and space-based telescopes

Abstract

We investigated several curved vane baffle designs coated with specular black paint as an inexpensive manufacturing alternative to traditional diffuse baffles vanes to reduce stray light and heat due to absorption in a standard Cassegrain telescope design configuration. The heat absorption is a very large problem in infrared systems and the specular designs solve this part of the problem. Our study involved simulating two different types of baffle systems, diffuse and specular painted vanes on the main barrel baffle. The first type of baffle consisted of evenly and non-evenly spaced diffusely black coated straight planar vanes on the main barrel baffle and a second type using specular black paint on curved vanes. TracePro, a stray light simulation software from Lambda Research Corporation, was used to simulate and compare each of the nine baffle systems for stray light rejection. The diffuse black painted straight vane baffle design was used as the baseline design to compare results to the other eight designs. In all designs except for the baseline design, TracePro's local downhill simplex optimization method was used to optimize each vane curvature and spacing in the main barrel baffle to reject incoming stray light. These curved vanes were designed to reject stray light back out of the main barrel baffle rather than to be absorbed by diffuse black paint.