In-fibre whispering gallery mode resonators: From isolated microspheres to coupled systems

摘要

We review here on a new, integrated in-fiber microresonator coupler, which is a combination of a microstructured optical fiber (MOF) and a microsphere; the last is encapsulated into the capillaries of the MOF. The light guided into the MOF core excites WGMs inside the encapsulated microsphere, manifested in out-scattering or transmission mode. Microspheres being made of polystyrene or BaTiO3 glass, have been infiltrated inside silica and germanosilicate core MOFs and their spectral response was measured. The operation of this composite light coupler has leaded to Q-factors greater than 3.5×103 for a single microsphere. Results related to the infiltration of several polystyrenes microspheres and the formation of coupled cavities inside a single MOF capillary and their spectral scattering characterisation will be shown. Finally, the tuning of the WGM spectrum of a BaTiO3 glass microsphere infiltrated inside a MOF by exploiting photorefractivity will be presented.