microrings
A microring is a small circular optical resonator that confines light by total internal reflection around its perimeter. Light travels in a ring and couples to an adjacent waveguide, enabling on-chip filtering, sensing, or lasing. Radii typically range from a few to a few tens of micrometers, with dimensions chosen to support circulating modes.
Microrings are commonly fabricated from silicon, silicon nitride, silicon dioxide, indium phosphide, or various polymers. The
Resonances follow m λ = n_eff 2πR, where n_eff is the effective index and m an integer. A
Fabrication typically uses lithography and etching on platforms such as silicon-on-insulator, silicon nitride, or III-V materials,
Applications include on-chip filters, wavelength-division multiplexing components, delay lines, and refractive-index or biosensing. When combined with