Inverse design of coherent supercontinuum generation using free-form nanophotonic waveguides

TL;DR

This paper introduces an inverse design approach for nanophotonic waveguides to optimize coherent supercontinuum generation, achieving broad, flat spectra from visible to mid-infrared wavelengths with experimental validation.

Contribution

It presents a novel inverse design method for free-form waveguides that enhances coherent supercontinuum generation in nanophotonics, surpassing traditional geometric limitations.

Findings

Successfully designed waveguides produce flat, coherent spectra

Experimental validation confirms numerical predictions

Broad spectral coverage from visible to mid-infrared achieved

Abstract

Many key functionalities of optical frequency combs such as self-referencing and broad spectral access rely on coherent supercontinuum generation (SCG). While nanophotonic waveguides have emerged as a compact and power-efficient platform for SCG, their geometric degrees of freedom have not been fully utilized due to the underlying nonlinear and stochastic physics. Here, we introduce inverse design to unlock free-form waveguides for coherent SCG. The efficacy of our design is numerically and experimentally demonstrated on Si3N4 waveguides, producing flat and coherent spectra from visible to mid-infrared wavelengths. Our work has direct applications in developing chip-based broadband light sources for spectroscopy, metrology, and sensing across multiple spectral regimes.