Nonlinear optical switches

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. 

Zhu, Y., et al., Multiwalled carbon nanotubes beaded with ZnO Nanoparticles for ultrafast nonlinear optical switching. Advanced Materials, 2006.18(5) p.587-592. 

Applications include eye glasses, spatial light modulation [31], optical waveguide construction [32], nonlinear optical switching [33], inks, and paints. 

N. Stevens, Nonlinear Optical Switching Properties of Dye-doped Inorganic/Organic Composite Films, Ph.D. thesis. The Graduate Center, New York, pp. 28-29 (2006). 

Photoinduced processes and resonant third order nonlinearity in poly(3-dodecylthiophene) has been studied by fs time resolved 4-wave mixing . Similar work has been reported for the poly(p-phenylene vinylene) system . Such materials have potential for the use as nonlinear optical switching devices. 

Near resonant z-scan studies provide both nonlinear refractive coefficients, ni, and two photon absorption coefficients, p. Results for a selection of PDAs in solution at 532 nm are given in Table 1. Diethylamino-PDA (lid) and the related quatemized polymer (15a) show comparable magnitudes of nonlinear absorption and refraction to those of poly-4-BCMU, with figures of merit, T, which satisfy the requirement for nonlinear optical switching devices. The metal-containing PDAs... 

Cavityless bistability employing self-phase modulation [3] nonlinear Fabry Perot bistability effect [14] intrinsic optical bistability [15] nonlinear optical switching near the total-internal reflection state [16], [17] bistability in guided wave geometry [18]. 

Toliver P., R. J. Runser, I. Glesk, and P. R. Pmcnal (2000) "Comjjarison of three nonlinear optical switch geometries," in Proc. Conf. on Lasers and Electro-Optics (CLEO 2000), San Francisco, CA, May 7-12, p>p.254-255. 

L., and Castet, F. (2007) Acido-triggered nonlinear optical switches benzazolo-oxazolidines. /. Phys. Chem. B, 111, 9795-9802. 

Castet, F., Champagne, B., Pina, F., and Rodriguez, V. (2014) A multistate pH-triggered nonlinear optical switch. ChemPhysChem, 15, 2221-2224... 

Enclosure also changes the redox properties of a compound, its color, and other physical properties (1,2). On this basis nonlinear optical materials, luminescence markers, controlled light switches, and other high-tech devices might be designed and prepared (15,17,137). 

Another group of conjugated thiophene molecules for future appHcations are those being developed as nonlinear optical (NLO) devices (75). Replacement of benzene rings with thiophene has an enormous effect on the molecular nonlinearity of such molecules. These NLO molecules are able to switch, route, and modulate light. Technology using such materials should become available by the turn of the twenty-first century. 

One of the advances in the field of PET is the design of molecular devices, in which D and A pairs are ingeniously linked by covalent bridges (B) to form D-B-A dyads. Electron transfers between D and A across B in a controlled manner may thus display useful functionalities, such as molecular rectifiers [25], switches [26], biosensors [27], photovoltaic cells [28], and nonlinear optical materials [29]. Spacers that have been utilized are versatile, including small molecules, such as cyclohexane [30], adamantane [31], bicyclo[2.2.2]octane [32], steroids [33], and oligomers of... 

By the sol-gel-process, inorganic glassy and hybrid polymeric materials are accessible at comparatively low temperatures [1], Therefore, organic molecules or dyes can easily be incorporated into the oxide matrix. This combination is especially attractive for the development of the following devices optical filters, solid-state lasers, optical switches, nonlinear optical laser hosts, optical data storage media, and photoconductive devices and films [2]. 

Nonlinear optical organic materials such as porphyrins, dyes, and phthalocyanines provide optical limiting properties for photonic devices to control light frequency and intensity in a predictable manner. The optical limit of CNTs composites is saturated at CNTs exceeding 3.8wt% relative to the polymer mass (Chen et al., 2002). Polymer/ CNT composites could also be used to protect human eyes, for example, optical elements, optical sensors, and optical switching (Cao et al., 2002). 

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