We present a geometrical optics model for the calculation of the internal fields in microspheres with nonlinear optical properties, which occur, for example, in stimulated Raman scattering. Our approach is based on a ray interpretation of the nonlinear wave equations describing the fields of the Stokes modes in a microdroplet. The Stokes modes are assumed to be whispering gallery modes. For such rays the nonlinear wave equations are used to describe the growth of the field along the path of the ray and to calculate the internal fields belonging to various Stokes modes. The interaction between different-order Stokes fields is considered, by using an iteration over the different orders. Although our approach can be extended to stimulated Brillouin scattering as well, in this paper only stimulated Raman scattering is considered.
© 2006 Optical Society of America
Original Manuscript: June 10, 2005
Revised Manuscript: September 6, 2005
Manuscript Accepted: September 15, 2005
Jörg Schulte, Thomas Weigel, and Gustav Schweiger, "Nonlinear processes in microdroplets: a geometrical optics approach," J. Opt. Soc. Am. B 23, 289-293 (2006)