Observation and Analysis of Whispering-Gallery-Mode in Microspheres by use of an Etch-Eroded Fiber Coupler

초록

We show that whispering-gallery-modes in microspheres can be efficiently excited by an etch-eroded fiber coupler. In this technique, the cladding of a single mode optical fiber is chemically etched away in order to attain good coupling between the fiber and the sphere. Using this simple and inexpensive technique, we successfully confirmed the whispering-gallery-mode resonances. The measured coupling efficiency between a 330mm sphere and a 7mm fiber core was about 15dB and the free spectral range was 1.6nm. The mode shift between TE and TM resonances was 0.4nm.