Nonlinear optical chromophore dipolar

For dipolar chromophores that are the subject of this chapter, only one component of the molecular hyperpolarizability tensor, Pzzz, is important. Thus, the summation in Eq. (8) disappears. Electric field poling induces Cv cylindrical polar symmetry. Assuming Kleinman [12] symmetry, only two independent components of the macroscopic second-order nonlinear optical susceptibility tensor... 

Clearly, a requirement for device quality second-order nonlinear optical materials is a noncentrosymmetric dipolar chromophore lattice. There are several ways by which such lattices have been achieved. With all methods, a force must... 

There have also been reports on the preparation of polar materials by a photo-electro-poling technique that combines the optically induced quadrupolar depletion of chromophores in the direction of the light electric vector with an additional field-induced orientation of dipolar chro-mophores. The latter allows the preparation of cold electrets, which are interesting for nonlinear optical applications, such as optical harmonic generation, wave mixing, etc. ... 

This work provides a relatively comprehensive review of studies involving ruthenium coordination and organometallic complexes as nonlinear optical (NLO) compounds/materials, including both quadratic (second-order) and cubic (third-order) effects, as well as dipolar and octupolar chromophores. Such complexes can display very large molecular NLO responses, as characterised by hyperpolarizabilities, and bulk effects such as second harmonic generation have also been observed in some instances. The great diversity of ruthenium chemistry provides an unparalleled variety of chromophoric structures, and facile Ru" —> Ru" redox processes can allow reversible and very effective switching of both quadratic and cubic NLO effects... 

Coe, B.J., Harris, J.A., Brunschwig, B.S., Garin, J., Orduna, J., Coles, S.J., Hursthouse, M.B. Contrasting linear and quadratic nonlinear optical behavior of dipolar pyridinium chromophores... 

This chapter concentrates on the design of efficient dipolar NLO chromophores and the different approaches for their incorporation in non-centrosymmetric materials, including guest-host polymer systems, chromophore-functionalized polymers (side-chain and main-chain), cross-linked chromophore-macromolecule matrices, dendrimers, and intrinsically acentric self-assembled chromophoric superlattices. The different architectures will be compared together with the requirements (e.g., large EO coefficient, low optical absorption, high stability, and processability) for their incorporation into practical EO devices. First, a brief introduction to nonlinear optics is presented. 

Am. Chem. Soc., 126,10418 (2004). Contrasting Linear and Quadratic Nonlinear Optical Behavior of Dipolar Pyridinium Chromophores with 4-(Dimethylamino)Phenyl or Ruthe-nium(II) Ammine Electron Donor Groups. 

Yu J, Cui Y, Wu C, Yang Y, Wang Z, O Keeffe M, Chen B, Qian G (2012) Second-order nonlinear optical activity induced by ordered dipolar chromophores confined in the pores of an anionic metal-organic fi amework. Angew Chem Int Ed 51 10542-10545... 

Second order optical nonlinearity can be induced in polymeric systems containing dipolar (donor-acceptor) chromophores. The chromophore can be a molecular species attached to the host chain or it can be incorporated in the polymeric structure itself. In general, a good chromophore has an electron donating group connected to an electron... 

Such a type of donor-acceptor complex represents an original class of 2D dipolar NLO chromophore, and EFISH and HRS experiments in combination with INDO/singles configuration interaction(SCI)-SOS theoretical calculations have been used to investigate the 2D character of the [3 response in 62 (A = C1) the 2D optical nonlinearity is related to the existence of various low-energy charge transfer states, and while... 

Although Zyss and Ledoux [32] have proposed the development and exploitation of octupolar chromophores, device development exploiting second-order optical nonlinearities has largely focused on dipolar chromophores of the form... 

Polymers for second-order NLO applications have been extensively investigated during the last ten years. However, significant progress in material development efforts toward practical applications has been made only in recent years. This chapter discusses the current state of the art in the development of second-order NLO polymers. We start with a brief description of the NLO phenomena at both the molecular and bulk levels. The design considerations and property optimization of chromophores are associated with the molecular level optical nonlinearity. The induced noncentrosymmetric dipolar orientation of chromophores leads to the bulk second-order NLO properties, which are most commonly char-... 

Dipolar chromophores must be assembled into a noncentrosymmetric lattice to translate molecular optical nonlinearity to maaoscopic electro-optic (EO) aaivity, which is one example of second-order NLO properties. The EO coefficient in units of pmV , rs3, is the principal element of the linear Pockel s EO effect tensor and denotes the magnitude of refractive index shift (Ai ) obtained for an applied low-frequency electric field. This... 

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