Nonlinear optical materials NLOs

Rare-earth jS-diketonate complexes with hemicyanine or related chromophotes have been studied for their potential as nonlinear optical materials (NLO materials). Such nonlinear optical materials could have applications in the domains of opto-electronics and photonics (Verbiest et al., 1997). Nonlinearity of the optical properties means that when a molecule is placed in an intense light beam, there is no linear relationship between the induced electric dipole moment and the applied electric field. When a molecule is subjected to an intense light field, the induced dipole moment is given by eq. (12). 

Second-order nonlinear optics (NLO) has several applications in the field of optoelectronics.11 Several of these nonlinear processes are straightforward to experimentally demonstrate but their application in devices has been hampered by the lack of appropriate materials. Necessary requirements for second-order nonlinear optical materials include the absence of centrosymmetry, stability (thermal and mechanical), low optical loss, and large and fast nonlinearities.8... 

Oscillators -NLO for lasers [NONLINEAR OPTICAL MATERIALS] (Vol 17) -parametric [LASERS] (Vol 15) -synthetic quartz crystals for [SILICA - SYNTHETIC QUARTZ CRYSTALS] (Vol 21)... 

Silica fibers - [SPECTROSCOPY, OPTICAL] (Vol 22) -coupling of NLO materials [NONLINEAR OPTICAL MATERIALS] (Vol 17) -use in infrared technology [INFRARED TECHNOLOGY AND RAMAN SPECTROSCOPY - INFRARED TECHNOLOGY] (Vol 14)... 

The field of nonlinear optics (NLO) is currently one of the most active in terms of research intensity and funding. However, despite many heroic efforts, both theoretical and experimental, the most common SHG-active materials that are in use today, potassium dihydrogenphosphate (KDP) and lithium niobate(V), LiNbO 3, were discovered when the field was in its infancy. Efforts now have to be concentrated on the development of processable, nonlinear optical materials, and this has to be achieved on a very short time scale. 

For the practical application of second-order NLO materials, not only a high hyperpolarizability but also good thermal stability is required. Heteroaryl diazo chromophores could also act as organic second-order nonlinear optical materials suitable for applications such as second... 

The extensive jt-delocalized system of metal-dithiolene complexes is also responsible for the nonlinear optical properties (NLO) which have been recently reviewed . The interaction of radiation with the matter induces an instantaneous displacement (polarization Pq = /X = aE, where a is the linear polarizability) of the electronic density away from the nucleus at small field (linear optics). At high fields (laser light) the polarizability of the molecule can be driven beyond the linear regime and a nonlinear polarization is induced (NLO) = aE + fiE" + y E + and for the bulk material... 

With few exceptions, a useful nonlinear optical material will be in the solid phase for example, a single crystal or a poled polymer embedded in a film. Ironically, the quantum chemical calculations of nonlinear optical properties have for the most part been concerned with a single microscopic species. Much has been learned in this way about appropriate molecular construction, but the ultimate goal must be to investigate the nonlinear optical (NLO) properties in the solid phase. 

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