Evidence for particle-shape sensitivity in the correlation between polarization states of light scattering

The cross correlation between polarization states of scattered laser speckl e as a function of scattering angle is observed for a range of spherical an d nonspherical particle suspensions. A variation in the degree of correlati on between polarization states is observed, and this information is indicat ive of the particle shape. A comparison with a theoretical model for small particles is made, suggesting that variations in polarization correlation w ith angle originate from the nonisotropic polarizability of nonspheres. Exp eriments are also performed on large spheroids and random-shaped polydisper sions, and the results indicate that the measurement method has significant potential for nonsphere detection and characterization. (C) 2001 Optical S ociety of America.