Multispectral infrared bidirectional reflectance distribution function forward-scatter measurements of common infrared black surface preparations and materials

Abstract

Fundamental to the design of an infrared sensor is controlling the stray light and internal radiation emission. A series of bidirectional reflectance distribution function (BRDF) measurements at two infrared bandpasses in the mid-wave infrared (MWIR) and long-wave infrared (LWIR) are acquired. Incident beams were oriented 10 and 60 deg from normal. Forward-scatter (key to baffles and cold shields) data are presented for infrared black surface preparations, including: anodizing, copper oxide, nickel oxide, black paints, and trademarked black surfaces. Comparison is also made between selected surfaces before and after exposure to 78 K (LN2) thermal cycles. This work also includes scanning electron microscope (SEM) images and discrete Fourier transform (DFT) measurements for selected black surfaces, including comparisons of damaged and undamaged nickel oxide. (C) 2006 Society of Photo-Optical Instrumentation Engineers.