Influence of two-photon absorption on third-order nonlinear optical processes as studied by degenerate four-wave mixing: The study of soluble didecyloxy subsituted polyphenyls

Article abstract of DOI:10.1063/1.460806

We have investigated the influence of two-photon absorption on the third-order nonlinear optical properties of model organic molecules using the technique of degenerate four-wave mixing (DFWM).A theoretical formulation developed here shows that the presence of two-photon absorption, which is related to the imaginary part of the third-order susceptibility χ⁽³⁾, leads to an enhancement of the effective third-order nonlinearity and to the appearance of effects caused by the formation of two-photon generated excited states.The dynamic behavior of the nonlinearity is then governed by the properties of excited molecules.The nonlinear effects also involve contribution which depend on the fifth power of the electric field.We have performed a systematic study of third-order nonlinear optical properties of alkoxy (-C10H21OCH) substituted p-polyphenyl oligomers using the technique of time-resolved degenerate four-wave mixing with subpicosecond pulses at 602 nm.Experimentally determined values of the second-order hyperpolarizability γ for the oligomers increase smoothly from the monomer to the trimer, with a more rapid increase to the pentamer and to the heptamer.In addition, the hyperpolarizabilities for the pentamer and the heptamer appear to be complex.A smooth increase of the γ value is expected from an increase of the ? conjugation from a shorter chain ligomer to a longer chain oligomer.The more rapid increase of the γ value in the pentamer, and especially in the heptamer, however, cannot be explained satisfactorily by only taking into account the ?-conjugation length.Two-photon absorption for the pentamer and the heptamer at the measurement wavelength of 602 nm is suggested to be important as the observed dynamic behavior is satisfactorily explained by the predictions of the theoretical model presented here.It is shown that the effective γ value for a two-photon absorbing material is a function of optical intensity, pulse width, and sample length if one uses the conventional degenerate four-wave mixing description.

Full text of DOI:10.1063/1.460806

Influence of twophoton absorption on thirdorder nonlinear optical processes as
studied by degenerate fourwave mixing: The study of soluble didecyloxy
substituted polyphenyls
Mingtang Zhao, Yiping Cui, Marek Samoc, Paras N. Prasad, Marilyn R. Unroe, and Bruce A. Reinhardt
Citation: The Journal of Chemical Physics 95, 3991 (1991); doi: 10.1063/1.460806
View online: http://dx.doi.org/10.1063/1.460806
View Table of Contents: http://scitation.aip.org/content/aip/journal/jcp/95/6?ver=pdfcov
Published by the AIP Publishing
Articles you may be interested in
Degenerate Four wave Mixing Studies and Ultrafast Optical Kerr Effect Measurements of Thirdorder
Nonlinear Optical Response in a Charge Transfer Organic Material
AIP Conf. Proc. 1391, 689 (2011); 10.1063/1.3643650
Twophoton absorption and second hyperpolarizability measurements in diphenylbutadiene by degenerate
fourwave mixing
J. Chem. Phys. 98, 2593 (1993); 10.1063/1.464141
Thirdorder nonlinearity and twophotoninduced molecular dynamics: Femtosecond timeresolved transient
absorption, Kerr gate, and degenerate fourwave mixing studies in poly (pphenylene vinylene)/solgel silica
film
J. Chem. Phys. 94, 5282 (1991); 10.1063/1.460512
Photoinduced processes and resonant thirdorder nonlinearity in poly (3dodecylthiophene) studied by
femtosecond time resolved degenerate four wave mixing
J. Chem. Phys. 93, 2201 (1990); 10.1063/1.459052
Dynamics of resonant thirdorder optical nonlinearity in perylene tetracarboxylic dianhydride studied by
monitoring first and secondorder diffractions in subpicosecond degenerate fourwave mixing
J. Chem. Phys. 91, 6643 (1989); 10.1063/1.457382
This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09

This article is copyrighted as indicated in the article. Reuse of AIP content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP:
193.0.65.67 On: Thu, 11 Dec 2014 16:38:09