Generation of Stimulated Raman Scattering of Radiation in a Spherical Microparticle
The study of generation of stimulated Raman scattering (SRS) of radiation in microparticles under exposure to high-intensity laser radiation is important, first of all, as there exist problems of Raman spectroscopy with respect to droplets concerning sensitivity and informative level . On the other hand, the literature actively discusses issues of generation of laser radiation at whispering gallery modes in microresonators, that is, when a microparticle serves as a microlaser [14,15]. The reviews of papers on these issues can be found, for example, in References 4, 13, 16.
The nature of stimulated radiation from a microspherical resonator is connected with generation of radiation being in resonance with Eigen modes of this particle. Therefore, both experimental and theoretical aspects of these two research fields have much in common. It should be noted that most publications on these issues are experimental. They consider physical principles and obtain quantitative data about such processes as SRS, stimulated Brillouin scattering (SBS), third harmonic generation, stimulated fluorescence, and lasing in microparticles. For the completion of these studies, it is necessary to have the consecutive quantitate description of the generation process, which would allow interpretation and correct explanation of experimental facts, as well as prediction of desirable results in new experiments.
In this chapter, we consider the theoretical description of the process of SRS of radiation in a transparent microparticle based on the method of expansion of the solution in series in eigen functions of the stationary linear scattering problem. The SRS effect is analyzed in a particle at the time of its origination and under stationary scattering conditions.