We have observed a large nonresonant third-order nonlinear susceptibility, X(3) (-ω; ω, 0, 0) in the isotropic phase of a nematic liquid crystal 4′-n-hexyl-4-cyanobiphenyl (K18). The highest value of X(3) obtained at 632.8 nm is 1.16274×10-18 m2V-2 corresponding to a temperature 29.3°C. The observed second-order pretransitional temperature T* from our measurements is 1.2°C below the first-order nematic to isotropic transition temperature. The dependence of the Kerr constant on (T-T*)-1 is found to be in good agreement with the predictions of the Landau-de Gennes model. © 1993 Chapman &amp; Hall.

Tetali A. Prasada Rao

Electrooptical devices

Optical properties

Phase Transitions

Thermal effects

CRYSTAL K18

NONRESONANT SUSCEPTIBILITY

Nematic liquid crystals

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IIT Madras

Nonresonant third-order susceptibility measurements in the nematic liquid crystal K18

Optical and Quantum Electronics

We report for the first time the determination of the real part of the third order nonlinear susceptibility χ(3)(-ω;ω,0,0) above the nematic to isotropic phase transition temperature of a nematic liquid crystal 4 (trans-4'-4'-n-pentylcyclohexy)-benzonirtile (PCH-5) from electro-optic Kerr effect experiments. The value of χ(3) observed at 632.8 nm is found to be 6.2079×10-19 m2 V -2 close to the phase transition temperature at 55.1°C.

Fulltext

Journal of Applied Physics

Nonresonant third order susceptibility measurements in a nematic liquid crystal-PCH-5

We report for the first time the determination of the real part of the third order nonlinear susceptibilities χ(3) (-ω, ω, 0, 0) in the isotropic phase of two nematic liquid crystals p-(ethoxybenzylidine)-p-butylaniline (EBBA) and p-(methoxybenzylidene)-p-butylaniline (MBBA) from electrooptic Kerr effect experiments. The highest value of χ(3) observed near nematic-to-isotropic transition temperature, at 632.8 nm is found to be 1.067×10-20 m2V-2 for EBBA and 6.602×10-20 m2V-2 for MBBA. © 1992 Chapman &amp; Hall.

Electrooptical Kerr constant and third-order susceptibility measurements in nematic liquid crystals and their mixtures

The performance of a high-voltage pulse measuring system based on the Kerr effect is investigated with benzoyl chloride, o-nitrotoluene, acetophenone, acetonitrile, benzaldehyde and ethyl methyl ketone for the first time along with nitrobenzene and acetone that are well known. These investigations have been carried out using high-voltage pulse fields ranging from 4*105 V m-1 to 107 V m-1. The experimentally determined electric field from the Kerr signal and the applied field show good agreement.

Measurement Science and Technology

A high-voltage pulse measuring system based on the Kerr effect

Measurement of Kerr constant and the non-resonant part of the static non-linear susceptibility χ(3)1212 (ω1,-ω1,o,o) in acetonitrile, benzaldehyde, acetophenone, acetone, ethyl methyl ketone, o-nitrotoluene, nitrobenzene, and benzoylchloride are reported. The variation of Kerr constant in nitrobenzene-benzene and o-nitrotoluene-benzene mixtures have also been experimentally determined for the first time for different molar fractions and compared with the theoretically obtained values using the mean field theory. The experimentally determined values of the dielectric constant(ε{lunate}) and the refractive index(n) have been used for the theoretical calculations. © 1991.

Journal of Molecular Liquids

Electro-optic Kerr effect studies in liquids and binary liquid mixtures.

The third-order nonlinear optical susceptibilityx(3) is measured in solutions of undoped and iodine-doped polyphenylacetylene by nanosecond degenerate four-wave mixing (DFWM). Phase conjugation in iodine-doped polyphenylacetylene is reported here for the first time. Polyphenylacetylene used in this work is polymerised with a group VI metal carbonyl as catalyst. Phase conjugate reflectivity is measured as a function of incident laser power, concentration and doping levels of iodine. Both undoped and iodine-doped polyphenylacetylene give good phase conjugate signals, with enhanced reflectivity in doped samples, at modest Q-switched laser power levels.x(3) for PPA in solution is found to be 1.1 x 10-20 m2/V2 and doping (22%) with iodine enhances it to 2 x 10- 18 m2/V2. © 1990.

Journal	Optical and Quantum Electronics
Publisher	Kluwer Academic Publishers
ISSN	03068919
Open Access	No