Bottle Microresonators Fabricated by Shaping Optical Fibers with a Beam of a CO2 Laser

The paper deals with the preparation, analysis of optical resonant properties and characterization of whispering-gallery-mode (WGM) bottle microresonators. These microresonators were prepared by a technique based on controlled tapering of a standard optical fiber with a focused beam of a CO2 laser. Resonant wavelengths and field distributions of whispering-gallery modes in the prepared microresonators were calculated numerically. The microresonators were excited by a laser diode using the evanescent field of a coupling element, namely a fiber taper. WGM resonances were determined from transmission spectra of the fiber taper. The prepared microresonators are intended for chemical detection purposes.