Radiative coupling of spherical micro dye lasers

Summary form only given. It is well known that dielectric spherical microparticles are optical resonators with high quality. For specific ratios x=particle perimeter/wavelength, surface waves are excited that circulate by total internal reflection within the particle and are superimposed to each other phase matched. If such a resonance is excited the amplitude of the electromagnetic field within the particle can be enhanced by orders of magnitude compared to the non-resonant case.