Coherent Control of the Non-instantaneous Nonlinear Power-law Response in Resonant Nanostructures

TL;DR

This paper demonstrates how to coherently control the nonlinear optical response in resonant nanostructures, revealing that maximum pulse intensity does not always produce the strongest nonlinear effects due to non-instantaneous dynamics.

Contribution

The authors develop a new theoretical approach to describe photoinduced nonlinearities in resonant nanostructures beyond traditional models.

Findings

Maximum nonlinear response is achieved at non-maximum pulse intensities.

Non-instantaneous, asymmetric photo-induced responses dominate the nonlinear behavior.

Theoretical model accurately captures complex nonlinear dynamics.

Abstract

We experimentally demonstrate coherent control of the nonlinear response of optical second harmonic generation in resonant nanostructures beyond the weak-field regime. Contrary to common perception, we show that maximizing the intensity of the pulse does not yield the strongest nonlinear power-law response. We show this effect emerges from the temporally asymmetric photo-induced response in a resonant mediated non-instantaneous interaction. We develop a novel theoretical approach which captures the photoinduced nonlinearities in resonant nanostructures beyond the two photon description and give an intuitive picture to the observed non-instantaneous phenomena.