Optical scattering from rough-rolled aluminum surfaces

Bidirectional, angular resolved scatterometry was used to evaluate the feas ibility of using rolled aluminum as reflectors in solar thermal collectors and solar cells. Two types of rolled aluminum with different surface roughn esses were investigated. The results show that the smoother of the two samp les [rms height, (0.20 +/- 0.02) mum] can be used as a nonimaging, concentr ating reflector with moderate reflection losses compared with those of opti cally smooth aluminum reflectors. The sample with the rougher surface [rms height, (0.6 +/- 0.1) mum] is not suitable as a concentrating element but c an be used as planar reflectors. The orientation of the rolling grooves is then of importance for minimizing reflection losses in the system. (C) 2001 Optical Society of America.