Ultrabroadband supercontinuum generation in dispersion-tailored Si3N4-LiNbO3-Si3N4 waveguides with structural parameter control

Ultra-broadband supercontinuum generation (SCG), particularly in the mid-infrared region, is important for applications such as molecular fingerprinting, multispectral imaging, and free-space communications. This study conducted numerical simulations to validate the feasibility of generating an ultra-broadband supercontinuum using a silicon nitride-lithium niobate-silicon nitride (Si3N4-LiNbO3-Si3N4) sandwiched waveguide structure. By establishing a pulse propagation model and analyzing dispersion profiles alongside phase-matching conditions, we systematically investigated the influence of structural parameters on phase-matching points and spectral broadening characteristics. The simulations successfully demonstrated an ultra-broadband supercontinuum spanning from the visible range (0.6 μm) to mid-infrared wavelengths (>4 μ m) at an intensity level of -80 dB. This work highlights the exceptional dispersion engineering offered by the layered architecture, establishing a foundation for wavelength-specific phase matching and customizable supercontinuum generation.