Inherent Limit to Coherent Phonon Generation under Non-Resonant Light Field Driving

TL;DR

This paper investigates the limits of coherent phonon generation under strong, non-resonant light fields, revealing a saturation effect due to inherent driving force limitations in the non-perturbative regime.

Contribution

It introduces a novel Floquet-based theoretical model explaining the saturation of coherent phonon generation under intense non-resonant light.

Findings

Saturation of phonon generation efficiency at high light intensities

Deviation from linear power dependence in the non-perturbative regime

Limitation of the driving force as the cause of saturation

Abstract

Coherent manipulation of quasi-particles is a crucial method to realize ultrafast switching of the relating macroscopic order. In this letter, we studied coherent phonon generation under strong light field which allows to induce non-perturbative nonlinear optical phenomena in solids. The efficiency of coherent phonon generation starts to saturate and deviate from the pronounced linear power dependence when the light intensity goes into the non-perturbative regime. We propose a novel theoretical model based on Floquet picture and show that the saturation is due to a limitation of the driving force inherent in non-resonant driving of the electronic system in the non-perturbative regime.