Figure 3
From: Laser-pointer-induced self-focusing effect in hybrid-aligned dye-doped liquid crystals
Nonlinear optical response in a hybrid-aligned cell and comparison with a homeotropic-aligned cell.
(a–d) Sketch of the arrangement (left) and self-diffraction ring observation at three light intensities (right). The homogeneous or homeotropic label on the sketch indicates which surface is facing the incident light and 0 or 90 indicates the angle between the rubbing direction and the laser polarization. (a) Homogeneous-90. (b) Homogeneous-0. (c) Homeotropic-90. (d) Homeotropic-0. (e) Number of diffraction rings as a function of light intensity for the hybrid-aligned cell and the homeotropic-aligned cell. The first ring appears only at 0.4 W/cm2 in the hybrid-aligned cell, indicating a reduction in the threshold by a factor of 8.5.
