Open AccessBiphotonic-induced reorientation inversion in azo-dye-doped liquid crystal films
Author(s) -
HongPing Lin,
Chih-Chien Chu,
Ming-Shian Li,
Andy Ying–Guey Fuh
Publication year - 2011
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.19.013118
Subject(s) - materials science , optics , liquid crystal , doping , green light , refractive index , laser , excitation , light intensity , green laser , crystal (programming language) , optoelectronics , blue light , physics , programming language , quantum mechanics , computer science
The reorientation inversion of liquid crystal molecules in azo-dye-doped liquid crystal (ADDLC) films irradiated by biphotonic (green and red light) lasers is studied using the self-phase-modulation method. The results show that the induced change of refractive index (∆n) in an ADDLC cell illuminated with a fixed intensity of green light increases with the red-light intensity. Notably, the value of ∆n is initially negative, and becomes positive when the intensity of the red laser is increasing. It is due to the fact that an extra positive torque is exerted on the LCs, which is produced by cis-isomers upon absorbing red light to compensate the negative torque induced by the excitation of the green light.