High-Q optical resonators in silicon-on-insulator-based slot waveguides

This letter describes the design, fabrication and characterization of high-$Q$ oval resonators based on slot waveguide geometries in thin silicon-on-insulator material. Optical quality factors of up to 27 000 were measured in such filters, and we estimate losses of −10 dB/cm in the slotted waveguides on the basis of our resonator measurements. Such waveguides enable the concentration of light to very high optical fields within nanoscale dimensions, and show promise for the confinement of light in low-index material with potential applications for optical modulation, nonlinear optics and optical sensing.