Current Technology Of Stray Light

Stray light analysis has matured in the last ten years into a set of well understood disciples, some of which are: the measurement and use of scatter data; baffle design; diffraction, system design, and system level analysis, to mention the most significant. Beyond the original goal of determining the background signal-to-noise ratio, it is not unusual for the analysis to play a significant role in the optical design tradeoffs, and in making a better light suppression system, and also to simplify the baffle complexity. System test results, both on the ground and in space, have confirmed the ability of the software analysis to make accurate predictions. The data base on the scattering characteristics of materials has swelled tremendously. The number of facilities making such measurements has also greatly increased. There are still some soft spots in certain areas of technology. Scatter measurements in the vacuum UV and far IR are still very scant. As better designs have led to better stray light suppression systems new problems have arisen. Currently, optical elements can be fabricated which would meet our needs, but the current state-of-the-art on contamination controls is not sufficient to keep them at their pristine level. Work is currently underway to solve this next challenge.