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Full-Text Articles in Physical Sciences and Mathematics
Enhanced Two-Photon Absorption In A Squaraine-Fluorene-Squaraine Dye: Design, Synthesis, Photophysical Properties, And Solvatochromic Behavior, William Moreshead
Enhanced Two-Photon Absorption In A Squaraine-Fluorene-Squaraine Dye: Design, Synthesis, Photophysical Properties, And Solvatochromic Behavior, William Moreshead
Electronic Theses and Dissertations
The discovery of any new technology is usually accompanied by a need for new or improved materials which make that technology useful in practical applications. In the case of two-photon absorption (2PA) this has truly been the case. Since its first demonstration in 1961, there has been an ever increasing quest to understand the relationships between two-photon absorption and the structure of two-photon absorbing materials. This quest has been motivated by the many applications for 2PA which have been reported, including fluorescence bioimaging, 3D microfabrication, 3D optical data storage, upconverted lasing, and photodynamic therapy. The work presented in this dissertation …
Squaraine Dyes, Design And Synthesis For Various Functional Materials Applications, Yuanwei Zhang
Squaraine Dyes, Design And Synthesis For Various Functional Materials Applications, Yuanwei Zhang
Electronic Theses and Dissertations
This dissertation contains the synthesis and characterization of squaraine based new functional materials. In the first part of this thesis work, a water soluble benzothiazolium squaraine dye was synthesized with pyridium pendents, and controlled aggregation properties were achieved. After formation of partially reversible J-aggregation on a polyelectrolyte (poly(acryl acid) sodium salt) template, the nonlinear, two-photon absorption cross section per repeat unit was found to be above 30-fold enhanced compared with nonaggregate and/or low aggregates. Using a similar strategy, sulfonate anions were introduced into the squaraine structure, and the resulting compounds exhibited good water solubilities. A ‘turn on’ fluorescence was discovered …
Prediction Of Optical Properties Of Pi-Conjugated Organic Materials For Technological Innovations, Iffat Nayyar
Prediction Of Optical Properties Of Pi-Conjugated Organic Materials For Technological Innovations, Iffat Nayyar
Electronic Theses and Dissertations
Organic π-conjugated solids are promising candidates for new optoelectronic materials. The large body of evidence points at their advantageous properties such as high charge-carrier mobility, large nonlinear polarizability, mechanical flexibility, simple and low cost fabrication and superior luminescence. They can be used as nonlinear optical (NLO) materials with large two-photon absorption (2PA) and as electronic components capable of generating nonlinear neutral (excitonic) and charged (polaronic) excitations. In this work, we investigate the appropriate theoretical methods used for the (a) prediction of 2PA properties for rational design of organic materials with improved NLO properties, and (b) understanding of the essential electronic …
Non-Degenerate Two Photon Gain In Bulk Gallium Arsenide, Brendan Turnbull
Non-Degenerate Two Photon Gain In Bulk Gallium Arsenide, Brendan Turnbull
Electronic Theses and Dissertations
The purpose of this thesis is to investigate the nonlinear phenomena known as doubly-stimulated, non-degenerate two-photon emission (ND-2PE) in Gallium Arsenide (GaAs). 2PE refers to the simultaneous emission of two-photons as electrons move from the conduction band in a direct gap semiconductor to the valence band. Following the same path for describing one-photon emission (1PE) we describe 2PE as a product of the irradiance, and the negative of the loss which in this case is two-photon absorption, , the negative coming from the population inversion. We attempt to observe 2PE by using a frequency non-degenerate pump-probe experiment in which a …