Nonlinear optical studies

Shen Y R 1994 Nonlinear optical studies of surfaces Appi. Rhys. A 59 541... 

This review has covered many of the essential features of the physical chemistry of nanocrystals. Rather than provide a detailed description of the latest and most detailed results concerning this broad class of materials, we have instead outlined the fundamental concepts which serve as departure points for the most recent research. This necessarily limited us to a discussion of topics that have a long history in the community, leaving out some of the new and emerging areas, most notably nonlinear optical studies [152] and magnetic nanocrystals [227]. Also, the... 

Figure 9. Tetraethynylethene (TEE) and diethynylethene (DEE) molecular scaffoldings, a) Donor-acceptor substituted chromophores for nonlinear optical studies, b) A three-way...

Nagy, A., Raicu, V., and Miller, R. J. D. 2005. Nonlinear optical studies of heme protein dynamics Implications for proteins as hybrid states of matter. Biochim. Biophys. Acta 1749 148-72. 

The low stability of the magnesium porphyrins has precluded most potential applications. Other metallotetrapyrroles have found industrial uses for oil desulfurization, as photoconducting agents in photocopiers, deodorants, germicides, optical computer disks, semiconductor devices, photovoltaic cells, optical and electrochemical sensing, and molecular electronic materials. A few scattered examples of the use of Mg porphyrins in nonlinear optical studies have appeared" and magnesium phthalocyanines have been used in a few studies as semiconductor or photovoltaic materials" " One of the few... 

Nonlinear optical studies were carried out using a combination of nonlinear absorption, self-focusing and degenerate four wave mixing measurements. The measurements were made using a Quantel Nano-Pico system that permits operation at either 10 ns or 100 ps pulse lengths at 1064 nm. The 10 ns pulses were TEM mode and temporally smoothed to a near gaussian (H). 

Spectroscopy A spectrum of PtPcCP4, which is typical of these phthalocyanines is shown in Fig. 2. The most intense band is the Q band which occurs between 640 nm and 680 nm for the different metal phthalocyanines. It is the lowest allowed n - n transition of the phthalocyanine ring. In dilute solution, the Q band of the monomer typically had a molar extinction coefficient of 2 x 105 //mole-cm in agreement with previous reports. (2) Additional bands, which have been assigned to phthalocyanine aggregates (2)(3), were observed on the short wavelength side of the Q band in the relatively concentrated solutions used for the nonlinear optical studies. 

Finally, because poly silanes show promise as photoresists (25, 26) and nonlinear optical materials (27), the fact that the rate of loss of excitons in poly(n-propylmethylsilane) by exciton-exciton annihilation becomes equal to the monomolecular loss rate at laser intensities of only 10 J/cm in a 5-ns pulse is significant. Because exposure levels are typically much higher for photoresist and nonlinear optical studies, exciton-exciton annihilation must be considered when attempting to understand the underlying photochemical reactions, because annihilation may dominate other photophysical and photochemical processes. 

A continuous research work on membrane properties and fundamental aspects of transport phenomena in the various membrane operations is important for the fumre of membrane science and technology. There is a need for both basic and applied research to develop new membranes with improved properties and new membrane processes. These research efforts must take into account the studies done in other areas such as supramolecular chemistry, molecular imprints materials, nanotechnology, nonlinear optics, studies on biological membranes and biological phenomena, etc. 

ULTRAFAST MAGNETIZATION DYNAMICS OF THIN Au/Fe FILMS NONLINEAR OPTICS STUDIES... 

Ultrafast magnetization dynamics of thin Au/Fe films nonlinear optics studies. 

Lanzafame J. M., Palese S., Wang D., Miller R. J. D. and Muenter A. A. (1994), Ultrafast nonlinear optical studies of surface reaction dynamics mapping the electron trajectory , /. Phys. Chem. 98, 11020-11033. 

A three dimensional extended dipole model which takes account of the interactions and alignment of molecules with carbazolyl chromophores in monolayer assemblies makes a useful contribution to the detailed understanding of the behaviour of layered structures . A number of other interesting papers involve a nonlinear optical study of Frenkel excitons in LB films where there are J aggregates of pseudoisocyanine iodide , an investigation of protonation equilibria and spectral... 

In a recent study, Ashwell et al. have observed that centrosymmetric squaraine dyes incorporated into LB monolayers showed second harmonic generation efficiencies, which compare favourably with the highest values hitherto reported for LB monolayers of noncentrosymmetric dyes [126]. Based on comparison of the absorption spectra and SHG characteristics of the LB films of squaraine 45 (Structure 15) as well as the effect of deposition pressure on these properties, it has been suggested that formation of noncentrosymmetric aggregates is responsible for these effects. Nonlinear optical studies have also shown that symmetric squaraines have quite large molecular second hyperpolarizabilities [127-131]. 

Hore DK, Walker DS, MacKinnon L, Richmond GL (2007) Molecular structure of the chloroform-water and dichloromethane-water interfaces. J Phys Chem C 111 8832-8842 Huang JY, Wu MH (1994) Nonlinear optical studies of binary mixtures of hydrogen bonded liquids. Phys Rev E 50 3737-3746... 

Hegde PK, Adhikari AV, Manjunatha MG, Sandeep CSS, Philip R. Nonlinear optical studies on new conjugated poly2,2 -(3,4-dialkoxy-thiophene-2,5-diyl) bis[5-(2-thienyl)-1,3,4-ox-adiazolejs. J Appl Polym Sci 2010 222 2641-50. 

Hegde PK, Adhikari AV, Manjunatha M, Suchand Sandeep C, Reji P. Nonlinear optical studies on a new poly2-(biphenyl-4-yl)-5-[3,4-didecyloxy-5 -(1,3,4-oxadiazol-2-yl)thiophen-2-yl]-l,3,4-oxadiazole. Mater Sci Forum 2010 657 56-61. 

D. McBranch, M. Sinclair, A. J. Heeger, A. O. Patil, S. Shi, S. Askari, F. Wudl, Linear and nonlinear optical studies of poly(p tm-phenylene vinylene) derivatives and polydiacetylene-4BCMU, Synthetic Metals 1989, 29, E85. 

Semiconductor lasers have certainly advanced to the stage where in the near future they will replace the more common solid state and gas lasers that have been the workhorses in both the scientific and industrial arenas. Semiconductor lasers will be successfully modelocked and the resultant ultrashort ophcal pulses will be amph-fled to peak power levels approaching the kilowatt region. This will have a tremendous impact on the ultrafast laser community, by providing an inexpensive, efficient, and compact source for ultrafast nonlinear optical studies. In addition, real-time optical signal processing and optical computing will take one step closer to reality with this advancement. 

Three new mainchain chromophoric polymers were synthesized and characterized. The physical properites of these polymers were compared to those of poly((4-N-ethylene-N-ethylamino)-a-cyanocinnamate). Films of the polymers can be made by either solution or melt casting of films. It was possible to obtain an oriented fibw of a polymer, namely poly(4 -[N-ethylene-N-(2-hydroxyethyl)amino] stilbene-4-formate, most likely because it has a melt transition temperature at around 210°C. Nonlinear optical studies of these polymers are in progress. 

We have Introduced the ideas of nonlinear optical studies into... 

Yee, H., Byers, J., and Hicks, J. (1994). A nonlinear optical study of chiral surfaces. Proc.SPlE, 2125 119-131. 

LE MOIGNE J., THIERRY A., CHOLLET P.A., KAJZAR F. and MESSIER J., (1988b), "Morphology Linear and Nonlinear Optical Studies of Poly[l,6-diCN-carbazolyl)-2,4 mexadiyne] Thin Films (pDCH)", J. Chem. Phys., 88, 6647-6654. 

Ultrafast nonlinear optical studies of surface reaction dynamics Mapping the electron trajectory. J. Phys. Chem. 98 11020-11033. 

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