Nonlinear optical properties of organic and polymeric materials
29 Sep 1983-
About: The article was published on 1983-09-29 and is currently open access. It has received 762 citations till now.
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TL;DR: In this article, the C=C bond length is 1-447 (6)]1, significantly longer than in ethylene, 1.336 (2)]1. Explanation for the observed low second harmonic generation efficiency (0.5 times that of urea) is provided.
Abstract: C 19Ha4N203.~xH 2 O, Mr= 347.5, monoclinic, C2, a = 15.473 (3), b = 6.963 (2), c = 20.708 (4) ]1, //=108.2(2) ° , V=2119(2)A 3, Z=4, Ox= 1.089 Mg m -3, ,~(Cu Ktx) = 1.5418 ]1, p = 0.523 mm -~, F(000) = 760.0, T= 293 K, R = 0.068 for 1967 unique reflections. The C=C bond length is 1-447 (6)]1, significantly longer than in ethylene, 1.336 (2)]1. The crystal structure is stabilized by O-H...O hydrogen bonding. Explanation for the observed low second-harmonic-generation efficiency (0.5 times that of urea) is provided.
4 citations
01 Jan 1989
TL;DR: The Hamiltonians are known as are methods to approach the many body solutions and can be used to scout trends without experimental checks as mentioned in this paper, however, the reliability of such calculations is not unquestionable and it is unrealistic to suggest they might now be used for scout trends.
Abstract: In the study of nonlinear optics in organic media structure-property relationships are of fundamental importance. In molecules, the relationships between perturbing fields and total dipolar polarization are often expressed as
$${\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{p}} = \mu + \alpha \bullet {\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{E}} + \beta \bullet \bullet \underline {EE} + \gamma \bullet \bullet \bullet \underline {EEE + \ldots .}$$
(1.1)
Limiting attention to the electronic portion, in the Born-Oppenheimer approximation, there is probably nothing involved that couldn’t be calculated with a powerful enough computer. The Hamiltonians are known as are methods to approach the many body solutions. However, the reliability of such calculations is not unquestionable and it is unrealistic to suggest they might now be used to scout trends without experimental checks. This must be true particularly with semiempirical methods for which the specific parameterizations which work well in some cases perhaps partly due to compensations of the methods’ approximations may not be so good for other classes of molecules or other calculated quantities. On the other hand, good experimentation is fraught with difficulties (1, 2). Certainly techniques have not evolved to the point of ease and reliability that “measurements” of β and γ are common. There is undeniably a need for a better empirical database against which to test our knowldege of nonlinear mechanisms. However, there are fundamental limitations to information that can be extracted from solution measurements, which are most often used to investigate larger molecules. No matter how well the solution susceptibilities are determined, there is uncertainty in the application of models of the liquid dielectric behavior. Even if the trivial models were correct, only a minimal part of the tensors’ properties can be determined. Thus theoretical anaylsis is essential to complete the picture of molecular polarization mechanisms and to predict the distribution of magnitudes within polarizability tensors.
4 citations
TL;DR: Crystals of Meta nitro aniline (mNA), an Organic nonlinear optical (NLO) material, were grown by slow solvent evaporation technique at room temperature by subjected to different characterization analyses.
Abstract: crystals of Meta nitro aniline (mNA), an Organic nonlinear optical (NLO) material, were grown by slow solvent evaporation technique at room temperature. Acetone was used as solvent. The mNA crystals obtained by the above technique were subjected to different characterization analyses. The lattice dimensions were determined from the single crystal x-ray diffraction analysis. The functional groups and optical behavior of the crystal was identified from FTIR and UV-vis analysis. Micro hardness and etching studies were also carried out on the sample respectively.
4 citations
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...Keywords: X-ray diffraction; Growth from solutions; nonlinear optic materials...
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TL;DR: The poled polymer glasses as discussed by the authors combine the attractive properties of the optical nonlinearities of organic molecules and the optical quality of polymer glasses, which can be used to fabricate high optical quality passive structures.
Abstract: Emerging guided-wave integrated optical technologies require suitable active devices and optical interconnects. Certain organic molecular materials possess the required optical nonlinearities for application in active devices. Glassy polymers, such as poly(methyl methacrylate), have been used to fabricate high optical quality passive structures. For application in integrated optics, requirements include high optical quality (low scattering and absorption losses), low dielectric constant, and suitable fabrication techniques.
We describe the preparation and optical properties of a new material, class, poled polymer glasses, which combines the attractive properties of the optical nonlinearities of organic molecules and the optical quality of polymer glasses. These materials are formed by incorporating organic compounds possessing large optical nonlinearities into a host material lacking long-range order. The orientational order is imparted to the composite system by applying a strong electric field at a temperature above the glass transition temperature, where molecular motion is enhanced, thereby aligning the optically nonlinear dopant molecules. By cooling the material through the phase transition with the field still applied, the orientational order is frozen in, and the composite material possesses second-order nonlinear optical properties.
4 citations
TL;DR: This chapter emphasizes those developments in the three classes of devices (light sources, modulators, and detectors) that address the optical processing needs and points out the specific promising directions for development.
Abstract: Publisher Summary This chapter emphasizes those developments in the three classes of devices (light sources, modulators, and detectors) that address the optical processing needs and points out the specific promising directions for development The performance of light sources, modulators, and detectors drives progress in the utilization of optical techniques in signal processing and computing Of the three device categories, optical sources are the most developed Most developments of relevance are pointed toward the improvements in semiconductor laser diodes to achieve better optical beam outputs because the advantages of such lasers in size, weight, and power efficiency are well known In optical processing applications, it is desired to manipulate the 2-D fields that are spatially as large as possible, that is, the photodetector throughputs must be commensurately large, even if the data array to be detected has been reduced in dimension to 1-D or even a single channel Optical processing architectures determine the format of the output data array, but the performance of photodetectors determines the efficacy of the alternative candidate architectures
4 citations