DETERMINATION OF REFRACTIVE-INDEXES OF DYED POLYMER MONOSPHERES

The complex refractive indices of commercial composite spherical particles (black dyed [D(p) = 1.041 mum] and red dyed [D(p) = 0.999 mum]) were determined by two different methods. The first method measured angular scattered-energy distributions to determine experimental phase functions that were compared with Mie phase functions. The second method examined several mixture rules to obtain the effective refractive indices of dyed polymer monospheres. The refractive indices of black and red dyes were measured independently for the mixture rule study. The effect of different refractive indices on the particle sizing accuracy was investigated using an optical liquid-borne particle counter and a wafer surface scanner.