Mimicking the nonlinear dynamics of optical fibers with waveguide arrays: towards a spatiotemporal supercontinuum generation

TL;DR

This paper numerically demonstrates how waveguide arrays with Kerr nonlinearity can mimic optical fiber dynamics to generate controllable, broad supercontinua through spatiotemporal diffractive resonant radiation, advancing optical device design.

Contribution

It extends the understanding of diffractive resonant radiation to spatiotemporal regimes in waveguide arrays, showing potential for novel supercontinuum sources.

Findings

Phase matching for diffractive resonant radiation applies in spatiotemporal case.

Linear potential shifts the pulse's central wavenumber.

Soliton self-wavenumber shift can be compensated by resonant radiation.

Abstract

We numerically demonstrate the formation of the spatiotemporal version of the so-called diffractive resonant radiation generated in waveguide arrays with Kerr nonlinearity when a long pulse is launched into the system. The phase matching condition for the diffractive resonant radiation that we have found earlier for CW beams also works well in the spatiotemporal case. By introducing a linear potential, one can introduce a continuous shift of the central wavenumber of a linear pulse, whereas in the nonlinear case one can demonstrate that the soliton self-wavenumber shift can be compensated by the emission of diffractive resonant radiation, in a very similar fashion as it is done in optical fibers. This work paves the way for designing unique optical devices that generate spectrally broad supercontinua with a controllable directionality by taking advantage of the combined physics of optical fibers and waveguide arrays.