D. S. Chemla

Bio: D. S. Chemla is an academic researcher. The author has contributed to research in topics: Bond dipole moment & Dipole. The author has an hindex of 1, co-authored 1 publications receiving 1926 citations.

Hyperpolarizabilities of the nitroanilines and their relations to the excited state dipole moment

Abstract: We have measured the second and third order hyperpolarizabilities of the three nitroaniline isomers and of two related molecules. For some isomers the intramolecular charge transfer is found to cause a very large enhancement of the second order polarizabilities. We present a theory relating this contribution to the first excited state of energy, oscillator strength, and dipole moment of the molecules. Experimental results are accounted for with an excellent accuracy.

Optical nonlinearities of conjugated molecules. Stilbene derivatives and highly polar aromatic compounds

Abstract: We have investigated the influence of donor and acceptor substituents on the second and third order hyperpolarizabilities β and γ of large conjugated molecules such as stilbene and styrene derivatives. This was performed by two independent measurements of β and γ using the techniques of dc electric‐field induced second‐harmonic generation and tunable four‐wave mixing in liquids and solutions. For trans−stilbene derivatives, β and γ are typically 10 times larger than for the corresponding benzene compounds, and are strongly correlated with the mesomeric effect of the substituents. A series of disubstituted molecules with strong donor–acceptor intramolecular charge transfer exhibit very large β, and it is shown that this enhancement can be predicted from the basic properties of the first electronic excited state.

Design and synthesis of chromophores and polymers for electro-optic and photorefractive applications

Abstract: The ability of nonlinear optical materials to transmit, process and store information forms the basis of emerging optoelectronic and photonic technologies. Organic chromophore-containing polymers, in which the refractive index can be controlled by light or an electric field, are expected to play an important role.

Organic Polymeric and Non-Polymeric Materials with Large Optical Nonlinearities

Abstract: Nonlinear optical properties are a sensitive probe of the electronic and solid-state structure of organic compounds and as a consequence find various applications in many areas of optoelectronics including optical communications, laser scanning and control functions, and integrated optics technology. Because of their strongly delocalized π electronic systems, polymeric and non-polymeric aromatic compounds show highly nonlinear optical effects. Nowadays, polymer chemists are able to tailor specific materials properties for various applications. Some organic substances with π electronic systems exhibit the largest known nonlinear coefficients, often considerably larger than those of the more conventional inorganic dielectrics and semiconductors, and thus show promise for thin-film fabrication, allowing the enormous function and cost advantages of integrated electronic circuitry. The electronic origins of nonlinear optical effects in organic π electronic systems are reviewed, with special emphasis being given to second-order nonlinear optical effects. Methods for measuring nonlinear optical responses are outlined, and the critical relationships of the propagation characteristics of light to observed nonlinear optical effects and to solid-state structure are discussed. Finally, the synthesis and characterization of organic crystals and polymer films with large second-order optical nonlinearities are summarized.