Design of a dispersion-engineered broadband Ge11.5As24Se64.5-Si3N4 strip–slot hybrid waveguide with giant and flat dispersion over 350 nm for on-chip photonic networks

We propose a new strip–slot hybrid waveguide with extreme large and flat dispersion over broad wavelength range. The strong resonance coupling between the strip and slot modes has been employed to obtain a high dispersion at desired wavelength. The properties of dispersion are analyzed using the finite-difference time-domain method. All numerical simulation results reveal that for the optimized waveguide structure, a maximum dispersion of ps nm km and dispersion full width at half-maximum of 2.5 nm at m are obtained. By cascading the strip–slot hybrid waveguides with varied width and height, a large and flattened dispersion of ps nm km covering 350 nm is achieved. Moreover, dispersion compensation of 100 Gbit/s return-to-zero on-off-keying optical-time-division-multiplexing signals after 50-km single mode fiber transmission, and after 7-km hollow-core photonic band-gap fiber transmission are demonstrated, separately. Such a waveguide will find widespread applications in on-chip all-optical signal processing.