Accession Number : ADA235622
Title : The Synthesis and Evaluation of Third-Order Optical Nonlinearities of Model Compounds Containing Benzothiazole, Benzimidazole and Benzoxazole Moieties.
Descriptive Note : Final rept. Feb 1988-Jul 1990,
Corporate Author : WRIGHT LAB WRIGHT-PATTERSON AFB OH
Personal Author(s) : Reinhardt, Bruce A. ; Unroe, Marilyn R. ; Prazak, Mark ; Evers, Robert C. ; Kane, James J. ; Jariwala, Chetan ; Sinsky, Mark ; Zhuo, Mingtang ; Samoc, Marek ; Prasad, Paras N.
Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA235622
Report Date : FEB 1991
Pagination or Media Count : 40
Abstract : A series of model compounds containing benzothiazole benzimidazole and benzoxazole moieties were prepared and evaluated by femtosecond degenerate four-wave mixing techniques. Model compounds were evaluated as either solutions of various concentrations in tetrahydrofuran or as vacuum deposited fils. In general, the trend toward nonlinearity was directly related to structural variations since no one- or two-photon resonances were observed in the models despite the consideration of time-response behavior and concentration dependence. The following generalizations are afforded: (1) microscopic third- order nonlinearity rapidly increases with an increase in the effective conjugation length for a quasi-one-dimensional molecule; (2) incorporation of a sulfur containing heteroaroamic fused ring in the conjugated structure enhances nonlinearity; (3) imidazole N-linkages enhance third-order optical nonlinearity by virtue of the transition from a quasi-one-dimensional to a two dimensional delocalization of the electrons without sacrifice of optical transparency and solubility.
Descriptors : *BENZIMIDAZOLES , *OPTICAL PROPERTIES , *BENZOXAZOLES , ELECTRONS , NONLINEAR SYSTEMS , LENGTH , RESONANCE , PHOTONS , SULFUR , SOLUBILITY , FURANS , HYDROXYL RADICALS , TRANSPARENCIES , MICROSCOPY , VACUUM , SYNTHESIS , OPTICS
Subject Categories : ORGANIC CHEMISTRY
Distribution Statement : APPROVED FOR PUBLIC RELEASE