Multiple coherent dispersive waves generation in silicon nitride slot waveguide

A method to generate multiple dispersive waves (DWs) with pumping in a normal dispersion regime is proposed. We show flexibility of producing four DWs in a silicon nitride (Si3N4) slot waveguide and explain the underlying dynamics of a four DWs generation process in detail, i.e., DWs emission via the optical wave-breaking phenomenon in an anomalous dispersion regime. Compression of the first anomalous DW results in the subsequent cascade DW generation. Combined with the soliton induced blue-shifted dispersive wave and red-shifted dispersive wave, the spectrum spans from visible to mid-IR with high coherence. The four DWs generation process has agreement with prediction of the phase-matching condition. Overall, this multiple DWs generation method in a Si3N4 waveguide provides the possibility for having an efficient, compact, and coherent mid-IR light source.