Optical whispering-gallery microresonators are useful tools in microphotonics, and non-linear optics at very low threshold powers. Here, we present details about the fabrication of ultra-high-Q whispering-gallery-mode (WGM) resonators made by CO2-laser lathe machining of fused-quartz rods. The resonators can be fabricated in less than one minute and the attained optical quality factors exceed Q=1x109. Demonstrated resonator diameters are in the range between 170 micron and 8 mm (free spectral ranges between 390 GHz and 8 GHz). Using these microresonators, a variety of optical nonlinearities are observed, including Raman scattering, Brillouin scattering and four-wave mixing.
Citation: Applied Physics Letters
Pub Type: Journals
Fused Silica, Laser Machining, Microresonator, Nonlinear Optics