Universal parameter to describe the reduction of refraction effects in the scattering of absorbing spheres

The scattered intensity from large spheres with a real part of the refractive index of n =1.33,1.5,2.0 is investigated as the radius R and an imaginary part of the refractive index κ are varied. It is shown that the product of κ and the size parameter k R , κ kR, is a universal parameter describing the quenching of the refraction phenomenon of the scattered light: the refraction hump, the generalized rainbows, and the glory. The physical reason for this is tha κ kR is the inverse of the relative skin depth of light penetration into the sphere, which is demonstrated by calculations of the internal fields that darken universally as κ kR increases.