A near-Lambertian diffuser for the infrared wavelength of 10.6 mu m th
at operates in both the transmission mode and the reflection mode has
been made. The diffuser is a porous sodium chloride window with the ph
ysical advantages and disadvantages of sodium chloride as an optical m
aterial. It is simple to manufacture because of the water solubility o
f the salt. The bidirectional scattering distribution function is near
ly flat for all scattering and incidence angles. In addition, the diff
user effectively depolarizes the scattered radiation. (C) 1997 Optical
Society of America