Broadened Low Anomalous Dispersion in Athermal Aluminum Nitride Hybrid Waveguides

An aluminum nitride hybrid waveguide is proposed to reduce the challenges brought on by high temperature sensitivity of microresonator-based devices. The waveguide is temperature-insensitive (athermal) and has an effective thermo-optic coefficient value of ±2 × 10 −6 /K in the wavelength range of 1412 to 1800 nm. It exhibits anomalous dispersion of less than 96 ps/nm/km over octave in the range of 1540 to 3234 nm. The nonlinear coefficient of the aluminum nitride waveguide is enhanced by the strong nonlinearity of titanium oxide. Application of the athermal waveguide in the optical frequency comb is simulated to prove its superior thermo-optic performance.