Nonlinear organics

A wide variety of other heterocyclic ring systems can conceivably serve as the conjugated backbone in nonlinear organic molecules. We will give examples from preliminary work on two of these, the thiazole and pyrimidine heterocycle derivatives 65-72 in Table VIII. These two heterocycles were chosen because the appropriate haloderivatives are commercially available as starting materials for nucleophilic aromatic substitution. The pyrimidine derivatives are of particular interest since their absorption edges ( 400 nm) are shifted hypsochromically an additional 30 nm relative even to the pyridines. 

Scientists Seek Nonlinear Organic Materials," Chemical and Engineering News, October 4, 1982, p.18. 

Nonlinear Organic Crystals Theoretical Concepts, Materials, and Optical Properties... 

Waveguiding and Waveguide Applications of Nonlinear Organic Materials... 

At this time, many of the parameters listed above have not been measured for nonlinear organic materials. Measurement will be necessary for an assessment of the full potential of such materials. To date, only a nonlinear directional coupler has been implemented in a nonlinear polymer, (poly-4BCMU). For this device at 1060 nm, the nonlinear response was dominated by two-photon absorption, and some limited switching attributable to absorption changes was observed (27). More recent work at 1030 nm appeared to show switching attributable to refractive nonlinearities (28). Clearly there is much progress to be made. 

We have presented a review of the salient features of nonlinear integrated optics. It appears that nonlinear organic materials can play an important role in second- and third-order guided-wave devices. This field requires a great deal of material characterization and processing, however, before significant advances are realized. 

In this study we suppose nonlinear organic material shows optical Kerr effect as n = n0+n2lEl2 and n2 = X<3)/(2n0). Moreover for simplification, we suppose the waveguides allow single mode propagations and TE polarization. After appropriate handling we get the following nonlinear coupled mode equations [ 12] ... 

Cerenkov doubling was also investigated in nonlinear organic crystals. The best results to date have been obtained with single crystals grown inside glass fibers. For example, DMNP was used to double into the blue and figures of merit of 40% W 1 cm-2 were obtained [51]. Unfortunately, the photostability proved to be the key problem. 

Are these phenomena unique, or are they typical of biological systems From a mathematical perspective, enzyme systems fall into a class of nonlinear organization, and a chain of enzyme reactions with negative feedback easily can demonstrate oscillatory behavior [520]. Glass has noted that in general, any nonlinear system with multiple negative feedback may demonstrate oscillations that lead to chaotic behavior [595]. 

Oliver, S. N Pantelis, P. and Dunn, P. L. (1990). Polymorphism and crystal-crystal transformations of the highly optically nonlinear organic compound q -[(4 -methoxyphenyl)methylene]-4-nitro-benzene-acetonitrile. Appl. Phys. Lett, 56, 307-9. [213]... 

Zyss, J. Nonlinear organic materials for integrated optics a review. J. Molec Electronics 1, 25-95 (1985). 

A detailed X-ray diffraction experiment and quantum-chemical calculations of N,N-dhnethyl-4-nitroaniline derivatives, also model compounds for optically nonlinear organic materials, revealed that the introduction of a substituent into the ortho- or meta-position with respect to the dimethylamino group resulted in decreasing the contribution of the... 

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