Resonance in modulation instability from non-instantaneous nonlinearities

TL;DR

This paper demonstrates experimentally and theoretically that resonance in modulation instability occurs in photorefractive crystals with non-instantaneous nonlinearities, enabling potential control over complex wave phenomena.

Contribution

It introduces the first observation and modeling of resonance in modulation instability caused by non-instantaneous nonlinearities in photorefractive materials.

Findings

Resonance enhances MI visibility at specific frequencies.

Theoretical models agree well with experimental results.

Resonance may enable control over chaotic and turbulent waves.

Abstract

To explore resonance phenomena in the nonlinear region, we show by experimental measurements and theoretical analyses that resonance happens in modulation instability (MI) from non-instantaneous nonlinearities in photorefractive crystals. With a temporally periodic modulation in the external bias voltage, corresponding to a modulation in the nonlinear strength, an enhancement in the visibility of MI at resonant frequency is reported through spontaneous optical pattern formations. Modeled by such temporally periodic nonlinear driving force to the system, theoretical curves obtained from a nonlinear non-instantaneous Schr\"{o}dinger equation give good agreement to experimental data. As MI is a universal signature of symmetry-breaking phenomena, our observation on the resonance in MI may provide a control on chaotic, solitary, and turbulence waves.