Quantitative Prediction of Two-Photon Absorption Cross Section Based on Linear Spectroscopic Properties

Abstract

We study two-photon absorption (2PA) spectra in a broad class of organic dye molecules, such as substituted diphenylaminostilbenes, push−pull porphyrins, and carbazol-substituted stilbenes. We show, for the first time, that the 2PA cross section in the lowest-energy dipole-allowed transition may be predicted with better than 50% absolute accuracy based solely on the molecular parameters obtained from linear spectroscopic measurements.

Alternative selection rules for one- and two-photon transitions in tribenzotetraazachlorin: Quasi-centrosymmetrical π-conjugation pathway of formally non-centrosymmetrical molecule

“…This parameter has the physical meaning of how much the permanent dipole moment changes upon excitation in two-level system. 38 Our estimation shows that α varies from 0.4 D (H 2 TtBuPc) and 0.9 D (H 2 TBTAC) to 1.8 D in free base tetraphenylporphyrin (H 2 TPP), 30 and 5.8 D in strongly pushpull-substituted porphyrin no. 7 in Ref.…”

New all-optical method for measuring molecular permanent dipole moment difference using two-photon absorption spectroscopy

“…In this case the 2PA is often well described by just two energy levels, and that s 2 value is directly related to D m ! [4]. This opens a new approach to measuring the molecular permanent dipole moment change.…”

“…Organic chromophores with large D m ! values are used as fluorescent biological markers [1], laser dyes [2], fast optical modulators [3], efficient multi-photon absorbers [4], as well as in many other practical applications. There are currently two basic ways of measuring D m !…”

“…The molecular 2PA cross-section, s 2 , may be expressed from quantum-mechanical perturbation theory as a function of transition dipole moments and permanent dipole moment differences between the states (sum-over-the-states model) [23][24][25]. We have recently shown that often in cases of practical interest good quantitative description is achieved already by accounting for two or three lower-energy states (few essential states model) [4,[26][27][28][29][30]. Here we focus on a special situation of the lowestenergy transition in dipolar chromophores.…”

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

“…[16] Rebane and coworkers used a theoretical approach based on the density matrix to show that parameters determined from a measurement of the linear absorption spectrum of a dipole transition can be used to determine the TPA crosssection at the one-photon absorption maximum. [17] For a broad range of molecules, the approach was shown to be yield TPA cross-sections that deviated at most by 50% compared with measurements. However, while these approximate techniques are useful for estimating the TPA cross-section, they do not predict the dispersion of the TPA cross-section, nor do they predict the first hyperpolarizability.…”