Sign inversion of the optical torque on the nematic director enhanced by anthraquinone dye dopants stable to the light action
✍ Scribed by V. Ya. Gayvoronsky; S. V. Yakunin; V. M. Pergamenshchik; V. G. Nazarenko
- Book ID
- 102445839
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 214 KB
- Volume
- 3
- Category
- Article
- ISSN
- 1612-2011
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✦ Synopsis
By analyzing the total and on-axis transmittance of the
laser beam we studied the enhanced light-induced director
reorientation (Jánossy effect) in a nematic liquid crystal
doped with anthraquinone dye molecules that do not have
photoinduced conformational transformations. The obtained
dependence on the angle between the light polarization E
and the initial director n
~0~ shows: first order director
reorientation (DR) transition with hysteresis for E ⊥
n
~0~; second order reversible DR transition with the
extremely low threshold intensity for E || n
~0~;
sign inversion of the nonlinear refractive index and DR in the
intermediate geometry. The data suggest a presence of two
different kinds of dipoles in the system: those absorbing light
and those giving rise to the nonlinear refractive index.