Third-order nonlinearities

Joo T, Jia Y, Yu J-Y, Lang M J and Fleming G R 1996 Third-order nonlinear time domain probes of solvation dynamics J. Chem. Phys. 104 6089... 

LB films of CO-tricosenoic acid, CH2=CH—(CH2)2qCOOH, have been studied as electron photoresists (26—28). A resolution better than 50 nm could be achieved. Diacetylenic fatty acids have been polymerized to yield the corresponding poly (diacetylene) derivatives that have interesting third-order nonlinear optical properties (29). 

The cadmium chalcogenide semiconductors (qv) have found numerous appHcations ranging from rectifiers to photoconductive detectors in smoke alarms. Many Cd compounds, eg, sulfide, tungstate, selenide, teUuride, and oxide, are used as phosphors in luminescent screens and scintiUation counters. Glass colored with cadmium sulfoselenides is used as a color filter in spectroscopy and has recently attracted attention as a third-order, nonlinear optical switching material (see Nonlinear optical materials). DiaLkylcadmium compounds are polymerization catalysts for production of poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVA), and poly(methyl methacrylate) (PMMA). Mixed with TiCl, they catalyze the polymerization of ethylene and propylene. 

Optical properties of cyanines can be usefiil for both chiral substituents/environments and also third-order nonlinear optical properties in polymer films. Methine-chain substituted die arbo cyanines have been prepared from a chiral dialdehyde (S)-(+)-2-j -butylmalonaldehyde [127473-57-8] (79), where the chiral properties are introduced via the chiral j -butyl group on the central methine carbon of the pentamethine (die arbo cyanine) chromophore. For a nonchiral oxadicarbocyanine, the dimeric aggregate form of the dye shows circular dichroism when trapped in y-cyclodextrin (80). Attempts to prepare polymers with carbocyanine repeat units (linked by flexible chains) gave oligomers with only two or three repeat units (81). However, these materials... 

Frequency-dependent polarizability a and second hyperpolarizability y corresponding to various third-order nonlinear optical processes have been... 

There have been very few measurements made on the physical properties of Tg derivatives, their relative greater difficulty of preparation when compared with the Tg analogs has meant little interest in their properties. However, TglOSiMeslg has been found to show photoluminescence in the blue region of the spectrum, third-order nonlinear optical properties for TgMeg have been modeled, and electronic properties for and TgMeg have been calculated. 

The physical properties of the expanded radialenes were greatly enhanced upon donor functionalization, leading to the stable derivatives 76-78 with fully planar conjugated rr-chromophores [110]. These compounds exhibit large third-order nonlinear optical coefficients, can be reversibly reduced or oxidized, and... 

Fig. 8. Examples of some of the donor-acceptor substituted TEEs prepared for the exploration of structure-property relationships in the second- and third-order nonlinear optical effects of fully two-dimensionally-conjugated chromophores. For all compounds, the second hyperpolarizability y [10 esu], measured by third harmonic generation experiments in CHCI3 solution at a laser frequency of either A = 1.9 or 2.1 (second value if shown) pm is given in parentheses. n.o. not obtained...

On the other hand, the nonlinear optical properties of nanometer-sized materials are also known to be different from the bulk, and such properties are strongly dependent on size and shape [11]. In 1992, Wang and Herron reported that the third-order nonlinear susceptibility, of silicon nanocrystals increased with decreasing size [12]. In contrast to silicon nanocrystals, of CdS nanocrystals decreased with decreasing size [ 13 ]. These results stimulated the investigation of the nonlinear optical properties of other semiconductor QDs. For the CdTe QDs that we are concentrating on, there have been few studies of nonresonant third-order nonlinear parameters. 

For the application of QDs to three-dimensional biological imaging, a large two-photon absorption cross section is required to avoid cell damage by light irradiation. For application to optoelectronics, QDs should have a large nonlinear refractive index as well as fast response. Two-photon absorption and the optical Kerr effect of QDs are third-order nonlinear optical effects, which can be evaluated from the third-order nonlinear susceptibility, or the nonlinear refractive index, y, and the nonlinear absorption coefficient, p. Experimentally, third-order nonlinear optical parameters have been examined by four-wave mixing and Z-scan experiments. 

Third-order nonlinear optical properties of CdTe QDs were examined by Z-scan and FWM experiments in the nonresonant wavelength region. We found that the two-photon absorption cross section, a, is as high as 10 GM, although this value decreases with decreasing size. In addition, the nonlinear response is comparable to the pulse width of a fs laser and the figures of merit (FOM = Re Xqd/ Xqd)... 

Wang, Y. and Herron, N. (1992) Size-dependent nonresonant third-order nonlinear susceptibilities of CdS clusters from 7 to 120 A. Int.J. Nonlinear Opt. Phys., 1, 683-698. 

Some quinones, having the ability to form intra- and/or intermolecular hydrogen bonds, exhibit high molecular hyperpolarizability and are third-order nonlinear optical (NLO) materials. Compound 39 has a %(3) of 5 x 10 11 esu at 1.9 pm, and is a third-order NLO material.23 The optoelectric properties of quinoid compounds correlate with their structures in crystals or on thin films.23... 

Ohta, K., M. Yang, and G. R. Fleming. 2001. Ultrafast exciton dynamics of J-aggregates in room temperature solution studied by third-order nonlinear optical spectroscopy and numerical simulations based on exciton theory. J. Chem. Phys. 115 7609-7621. 

Whittall, Ian R., McDonagh, Andrew M., Humphrey, Mark G., Organometallic Complexes in Nonlinear Optics 11 Third-Order Nonlinearities and Optical... 

Dirk CW, Cheng L, Kuzyk MG (1992) A simplified three-level model describing the molecular third-order nonlinear optical susceptibility. Int J Quantum Chem 43 27-36... 

Kuzyk MG, Dirk CW (1990) Effects of centrosymmetry on the nonresonant electronic third-order nonlinear optical susceptibility. Phys Rev A 41 5098-5109... 

Hales JM, Zheng S, Barlow S, Marder SR, Perry JW (2006) Bisdioxaborine polymethines with large third-order nonlinearities for all-optical signal processing. J Am Chem Soc 128 11362-11363... 

Gubler, U. and Bosshard, C. Molecular Design for Third-Order Nonlinear Optics. Vol. 158, pp. 123-190. 

Gray, G. M. Lawson, C. M. Structure-Property Relationships in Transition Metal-organic Third-order Nonlinear Optical Materials. In Optoelectronic Properties of Inorganic Compounds, Roundhill, D. M., Fackler, J. P., Jr., Eds. Plenum New York, 1999 pp 1-27. 

Hill, C. A. S. Underhill, A. E. Winter, C. S. Oliver, S. N. Rush, J. D. Resonance Enhanced Third-order Nonlinearities in Metal Dithiolenes. In Organic Materials for Nonlinear Optics II Hann, R. A., Bloor, D., Eds. Royal Society of Chemistry London, 1991, pp 217-222. 

In the first part of this paper several novel approaches to the alignment problem of second-order nonlinearity will be presented. The molecular information which guided and motivated these efforts, and others described in this symposium, derives from third-order nonlinear optical experimentation (EFISH and others). In the second... 

Characterizations bv Third-Order Nonlinear Optical Experimentation... 

Two straightforward third-order nonlinear optical phenomena which are used to characterize ft and y are EFISH and THG (2)... 

New THG Methods For Molecular Liquid Characterization. An area which is essential for understanding general third-order nonlinear polarizability is characterization of the purely electronic contributions (48). Several methods have been employed for this... 

Third-Order Nonlinear Susceptibility in Multilayers of Polydiacetylene... 

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