Quantum-classical modeling of nonlinear pulse propagation in a dissolved two-photon active chromophore.
In the present work we outline the implications of a quantum-classical approach for modeling two-photon absorption of organic chromophores in solution. The approach joins many-photon absorption dynamic simulations with quantum chemical first principles calculations of corresponding excitation energies and transition matrix elements. Among a number of conclusions of the study, we highlight three: (i) The use of either short- or long-pulse excitation is demonstrated to switch the absorptive capacity of the nonlinear medium owing to enhancement of the nonlinear stepwise processes; (ii) The two-photon cross section strongly depends on the way in which the dephasing rate decays when the laser frequency is tuned off-resonant with the corresponding molecular transition; (iii) The results of the pulse propagation simulations based on electronic structure data obtained with a new Coulomb attenuated functional is shown to be in much better agreement with the experimental results than those based on data received with traditional density functionals.
Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo, New York 14260-3000, USA. abaev@buffalo.edu
Alexander
A
Baev
Pawel
P
Salek
Faris
F
Gel'mukhanov
Hans
H
Agren
D000042:Absorption; D000465:Algorithms; D004583:Electrons; D005449:Fluorenes / Q000737:chemistry*; D017711:Nonlinear Dynamics; D017785:Photons; D011789:Quantum Theory
D005449:Fluorenes