In the small-angle approximation, the exact solution of an equation of radiative transfer is cast in a series form suitable for numerical computation. This is used to calculate the radiance produced by a cw laser beam. For the medium with Gaussian phase function, a convergent numerical procedure is described. Explicit results for the scattered radiance, obtained for a wide range of parameters, display the existence of three well-defined regions on the plots of radiance versus transverse distance. A comparison of the exact theory with two approximate approaches is carried out.
© 1979 Optical Society of AmericaPDF Article