Supercontinuum Generation by Saturated Second-Order Nonlinear Interactions

TL;DR

This paper introduces a novel supercontinuum generation method using saturated second-order nonlinear interactions in nanowaveguides, supported by a heuristic model and scaling laws, promising lower energy requirements.

Contribution

The work presents a new approach to supercontinuum generation leveraging saturated second-order nonlinear effects, with validated models and scaling laws for efficient broadband light sources.

Findings

Model agrees well with experimental results

Scaling laws relate energy to pulse parameters

Potential for lower-energy supercontinuum sources

Abstract

We propose a new approach to supercontinuum generation and carrier-envelope-offset detection based on saturated second-order nonlinear interactions in dispersion-engineered nanowaveguides. The technique developed here broadens the interacting harmonics by forming stable bifurcations of the pulse envelopes due to an interplay between phase-mismatch and pump depletion. We first present an intuitive heuristic model for spectral broadening by second-harmonic generation of femtosecond pulses, and show that this model agrees well with experiments. Then, having established strong agreement between theory and experiment, we develop scaling laws that determine the energy required to generate an octave of bandwidth as a function of input pulse duration, device length, and input pulse chirp. These scaling laws suggest that future realization based on this approach could enable supercontinuum generation with orders of magnitude less energy than current state-of-the-art devices.