Sub-Cycle Optical Response Caused by Dressed State with Phase-Locked Wavefunctions

TL;DR

This paper demonstrates sub-cycle optical response modulation in a GaAs quantum well driven by a terahertz pulse, revealing phase-locked dressed states' role in coherent light-matter interactions.

Contribution

It provides experimental evidence and analytical modeling of sub-cycle optical absorption modulation caused by phase-locked dressed states in a semiconductor quantum well.

Findings

Optical absorption modulated on sub-cycle timescale

Good agreement with analytical susceptibility formula

Coherent reshaping of probe intensity via excitonic sidebands

Abstract

The coherent interaction of light with matter imprints the phase information of the light field on the wavefunction of the photon-dressed electronic state. Driving electric field, together with a stable phase that is associated with the optical probe pulses, enables the role of the dressed state in the optical response to be investigated. We observed optical absorption strengths modulated on a sub-cycle timescale in a GaAs quantum well in the presence of a multi-cycle terahertz driving pulse using a near-infrared probe pulse. The measurements were in good agreement with the analytical formula that accounts for the optical susceptibilities caused by the dressed state of excitons, which indicates that the output probe intensity was coherently reshaped by the excitonic sideband emissions.