A Minimized SiO $_{2}$ Waveguide With an Antiresonant Reflecting Structure for Large-Scale Optical Integrations

A minimized SiO₂ waveguide with an antiresonant reflecting buffer, a SiO₂ core, and an air cladding is presented. The buffer includes multiple periods of antiresonant reflecting structure to lower leakage loss to the substrate. Theoretically speaking, when there are three periods of etch-through antiresonant reflecting structures, one obtains a straight minimized SiO ₂ waveguide with a low leakage loss (<0.01 dB/cm) and a bending radius as small as 15 mum (because of the large index contrast between the core (SiO₂) and the air cladding in the lateral direction)