Tunable Large Dispersion in Hybrid Modes of Lithium Niobate-on-Insulator Multimode Waveguides

We report a large group velocity dispersion of hybrid modes in a LiNbO3-on-insulator multimode rib waveguide. A peak dispersion of ±49000 ps/(nm.km) is obtained in the mode hybridization region between TE
₀₀
and TM
₁₀
modes with a full width at half maximum of 10 nm. Dispersion for hybrid modes is tunable around ±15000 ps/(nm.km), ±22000 ps/(nm.km), and ±49000 ps/(nm.km) occurring at wavelengths of 1272, 1372, and 1496 nm, respectively, in the telecommunication band. In the wavelength range from 1530 to 1600 nm, the proposed rib waveguide is free of hybrid modes. In this region, the waveguide exhibits a flat dispersion profile for all eight guided modes with a maximum <;1000 ps/(nm.km).