Fluorescence driven by nonclassical light

TL;DR

This paper explores whether squeezed light can enhance two-photon excitation in atomic systems and assesses the detectability of such enhancements in experiments, considering realistic broadening effects.

Contribution

It develops a model including broadening effects to evaluate fluorescence under classical and squeezed light, demonstrating potential but moderate enhancements in atomic systems.

Findings

Squeezed light can enhance two-photon excitation under ideal conditions.

Enhancements are detectable but moderate compared to molecular systems.

Both continuous-wave and pulsed regimes show potential for enhancement.

Abstract

We investigate whether or not irradiation by squeezed light can provide an enhancement of the two-photon excitation of a system over irradiation by classical light. Our emphasis is not only on whether or not there is such an enhancement, but also on whether or not any enhancement can be reasonably detected in an experiment. We begin by developing a model that includes radiative and nonradiative broadening to calculate the total scattered and absorbed energy. As an example calculation, we consider cesium atoms in a magneto-optical trap, and evaluate the fluorescence emission when driven by non-degenerate classical and squeezed light, in both the continuous-wave and pulsed regimes. We find that squeezed light can provide an enhancement in both regimes under ideal circumstances. These enhancements are in principle detectable. However, we stress that they are moderate at best compared to recently reported values for molecular systems.