Partial nonlinear reciprocity breaking through ultrafast dynamics in a random photonic medium

TL;DR

This paper demonstrates that ultrafast nonlinear dynamics can break reciprocity in a random photonic medium, leading to suppression of coherent backscattering and enabling new control over light transport.

Contribution

It introduces a novel mechanism of reciprocity breaking via ultrafast nonlinear effects in disordered media, supported by experimental and simulation results.

Findings

Ultrafast nonlinear dynamics suppress coherent backscattering.

Reciprocity breaking occurs during the probe's dwell time.

Monte Carlo simulations accurately reproduce the effect.

Abstract

We demonstrate that ultrafast nonlinear dynamics gives rise to reciprocity breaking in a random photonic medium. Reciprocity breaking is observed via the suppression of coherent backscattering, a manifestation of weak localization of light. The effect is observed in a pump-probe configuration where the pump induces an ultrafast step-change of the refractive index during the dwell time of the probe light in the material. The dynamical suppression of coherent backscattering is reproduced well by a multiple scattering Monte Carlo simulation. Ultrafast reciprocity breaking provides a distinct mechanism in nonlinear optical media which opens up avenues for the active manipulation of mesoscopic transport, random lasers, and photon localization.