Experimental verification of a self-consistent theory of the first-, second-, and third-order (non)linear optical response

TL;DR

This paper presents a self-consistent experimental and theoretical approach to accurately determine nonlinear optical properties of dyes, using multiple spectroscopy techniques and sum rules to reduce parameters without adjustable variables.

Contribution

It introduces a novel method combining spectroscopy and sum rules for parameter reduction, enabling precise, parameter-free predictions of nonlinear optical responses.

Findings

Predicted two-photon absorption cross-section matches experimental data.

Method achieves self-consistency across multiple measurement techniques.

Reduces parameter space using sum rules and molecular symmetry.

Abstract

We show that a combination of linear absorption spectroscopy, hyper-Rayleigh scattering, and a theoretical analysis using sum rules to reduce the size of the parameter space leads to a prediction of the two-photon absorption cross-section of the dye AF455 that agrees with two-photon absorption spectroscopy. Our procedure, which demands self-consistency between several measurement techniques and does not use adjustable parameters, provides a means for determining transition moments between the dominant excited states based strictly on experimental characterization. This is made possible by our new approach that uses sum rules and molecular symmetry to rigorously reduce the number of required physical quantities.