A Specular Chamber for Off-Axis Response Evaluations of High-Rejection Optical Baffling System,

摘要

A special chamber for measuring the off-axis response of high-rejection optical baffling systems was designed and constructed. The ambient background power level caused by atmospheric scattering was reduced by using high-efficienty particulate filters to remove the atmospheric aerosols and produce a clean-room environment. The effects of surface scattering were reduced by using specular surfaces in a modified cylindrical shape to direct the scattered radiation away from the baffle entrance. Two computer programs were used to predict the magnitudes of the atmospheric and surface scattering. Measurements which separated the atmospheric scattering from the surface scattering were performed. Rayleigh (molecular) scattering was determined to be the limiting mechanism in achieving a low background.