Efficient coupling of free propagating light into Whispering Gallery Modes

Whispering Gallery Mode resonators are dielectric structures with cylindrical symmetry. They typically excited an evanescent field leaking out of a tapered fiber or waveguide. It is also known that they can be free propagating beams. In this work, we use recently developed analytical model which quantitatively describes the coupling beams into Modes for spherical particles. Using model, have been able to theoretically quantify mode purity and efficiency resonant order j * = 1456. We observed transverse position beam plays crucial role in determining efficiency. Last but not least, verified as well Q-factor predicted by our outstanding agreement experimental values measured on microresonator same dimensions simulated one.