Two-photon induced fluorescence of organic molecules in microcavity

The problem about two-photon induced fluorescence of organic dye active molecules located in spherical transparent microparticles at the ultrashort laser pulses influence was theoretically investigated. The system of kinetic equations for laser generation was written taking into account stimulation transitions. Generation regimes of stimulated radiation were found. Resonator properties of spherical microparticles were theoretically investigated using the method of expanding optical fields into series of eigenfunctions. The breakdown of the beginning of stimulated radiation in the microparticle was determined. It was shown that stimulated radiation intensity depends on degree of its spatial overlap with all other modes of the pump radiation. The interpretation of experimental data of two-photon induced fluorescence in the particles with organic dye was carried out.