Temperature stabilized dielectric based on-chip interferometers

Abstract

A device has a dual-geometry waveguide structure with an input, an output and two coupler structures optically coupled using arms of different optical path lengths. Each arm has a first passive waveguide having a first length and a dual-core waveguide geometry, coupled by a transition structure to a second passive waveguide having a second length and a single-core waveguide geometry. Optical mode confinement is larger in the first passive waveguide than in the second passive waveguide. The first and second lengths are selected such that a temperature sensitivity of optical path length difference of the dual-geometry waveguide structure is lower than a temperature sensitivity of optical path length difference that would characterize a standard waveguide structure differing from the dual-geometry waveguide structure in that no transition structure is present within either arm of the standard waveguide structure, each arm of the standard waveguide structure either excluding any waveguide having a dual-core waveguide geometry or excluding any waveguide having a single-core waveguide geometry.