1.
Eur Phys J E Soft Matter
; 35(1): 4, 2012 Jan.
Artigo
em Inglês
| MEDLINE
| ID: mdl-22270454
RESUMO
We use Z-scan technique to investigate the nonlinear optical response of the thermotropic liquid crystal E7 in the neighborhood of the nematic-isotropic phase transition. The analysis of the data for the nonlinear optical birefringence is compatible with an effective critical exponent of the order parameter, ß = 0.28 ± 0.03, which is close to the classical value, ß = 0.25 , for a tricritical point. The nonlinear optical absorption in the nematic range depends on the geometrical configuration of the nematic director with respect to the polarization beam, and vanishes in the isotropic phase.