Excitation and recording of morphology-dependent resonances in spherical microresonators by hollow light guiding fibers

We report the excitation and simultaneous recording of morphology-dependent resonances in dye-doped microresonators by a single hollow fiber. The spherical microresonator was plugged in the tapered end of a light guiding flexible hollow fiber. Light from a frequency-doubled Nd:YVO4 laser was coupled via a beam splitter into one end of the hollow fiber and transported to the resonator mounted on the tapered end of the fiber. Fluorescence was excited in the resonator. This fluorescence was partly coupled in the hollow fiber and guided back to the untapered end. Here, the fluorescence was separated from the laser light by a beam splitter and analyzed spectroscopically. The tapered fiber was prepared by heating with a CO2 laser. (C) 2004 American Institute of Physics.