Coupling of a near-field probe to whispering gallery modes in a microsphere

Summary form only given. Optical microsphere resonators are attractive systems for both fundamental physics research in the field of cavity quantum electrodynamics and for the use in optoelectronic devices. So-called whispering-gallery modes of such cavities feature extreme photonic confinement with very small mode volume and a very high quality (or Q-) factor. Here, we report on a new experiment where we couple a single mode fiber tip to individual modes of a microsphere resonator. In order to acheive coupling; the tapered fiber tip is placed close to the sphere surface and light from the evanescent field on the sphere surface scatters into the fiber.