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.

Tetali A. Prasada Rao

Fulltext

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

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IIT Madras

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

Journal of Applied Physics

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.

Optical and Quantum Electronics

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

In this paper, we report for the first time the determination of the real part of the third-order nonlinear susceptibility, x(3) (–ω, ω, 0, 0), measurements in the isotropic phase of a nematic liquid crystal 4ʹ-n-pentyl-4-cyanobiphenyl (KI 5) from electro-optic Kerr effect experiments . The value of x(3) obtained at 632.8 run is found to be 1 .08 × 10-18 m2 V-2 corresponding to a temperature 35. 5 ° C and is the highest so far reported to the best of our knowledge. © 1993 Taylor &amp; Francis Ltd.

Journal of Modern Optics

Third-order susceptibility measurements in a nematic liquid crystal-k15

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

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	Journal of Applied Physics
ISSN	00218979
Open Access	No