Enhancing entangled two-photon absorption of Nile Red via temperature-controlled SPDC

TL;DR

This paper presents a theoretical model for entangled two-photon absorption in dyes, highlighting the influence of phase-matching temperature, and validates it with experiments on Nile Red, advancing understanding of quantum fluorescence processes.

Contribution

The paper introduces a new simulation approach for entangled two-photon absorption considering chemical properties, improving prediction accuracy for complex dyes.

Findings

Absorption probability depends strongly on phase-matching temperature.

The model accurately predicts experimental results for Nile Red.

Temperature control enhances entangled two-photon absorption efficiency.

Abstract

Entangled two-photon absorption can enable a linear scaling of fluorescence emission with the excitation power. In comparison to classical two-photon absorption with a quadratic scaling, this can allow fluorescence imaging or photolithography with high axial resolution at minimal exposure intensities. However, most experimental studies on two-photon absorption were not able to show an unambiguous proof of fluorescence emission driven by entangled photon pairs. On the other hand, existing theoretical models struggle to accurately predict the entangled two-photon absorption behavior of chemically complex dyes. In this paper, we introduce an approach to simulate entangled two-photon absorption in common fluorescence dyes considering their chemical properties. Our theoretical model allows a deeper understanding of experimental results and thus the occurrence of entangled two-photon absorption. In particular, we found a remarkable dependency of the absorption probability on the phase-matching temperature of the nonlinear material. Further, we compared results of our theoretical approach to experimental data for Nile Red.