Super-resonant radiation stimulated by high-harmonics

TL;DR

This paper reveals a new super-resonant radiation phenomenon stimulated by high-harmonics in soliton propagation, achieving unprecedented intensity levels and demonstrating its universality across different dispersion regimes and harmonic orders.

Contribution

It introduces the concept of super-resonant radiation stimulated by high-harmonics, with experimental evidence in diamond, expanding understanding of soliton-induced radiation phenomena.

Findings

Resonant radiation can be parametrically stimulated with high gain.

Super-resonant radiation can reach intensities comparable to the soliton.

The mechanism is universal across dispersion regimes and harmonic orders.

Abstract

Solitons propagating in media with higher order dispersion will shed radiation known as dispersive wave or resonant radiation, with applications in frequency broadening, deep UV sources for spectroscopy or simply fundamental studies of soliton physics. Starting from a recently proposed equation that models the behaviour of ultrashort optical pulses in nonlinear materials using the analytic signal, we find that the resonant radiation associated with the third-harmonic generation term of the equation is parametrically stimulated with an unprecedented gain. Resonant radiation levels, typically only a small fraction of the soliton, are now as intense as the soliton itself. The mechanism is quite universal and works also in normal dispersion and with harmonics higher than the third. We report experimental hints of this super-resonant radiation stimulated by the fifth harmonic in diamond.