CONFIGURATION TRANSITIONS OF NEMATIC DROPLETS IN PDLC

A general equilibrium equation, including the saddle-splay elastic con stant K-24, of director configurations of nematic droplets in PDLC wit h weak homeotropic anchoring is obtained. Numerical simulation shows t hat: 1) A transition from the axial structure to the bipolar structure occurs at certain threshold value of the ratio of the anchoring stren gth sigma and the electric field strength xi; 2) A nearly homogeneous orientation of the directors occurs when sigma/xi decreases to a certa in value; 3) Increasing sigma/xi can induce a transition from the radi al structure to the axial structure; 4) K-24 is insensitive to both th e radial structure and the axial structure. Optical patterns of drople ts with different configurations viewed under polarized optical micros cope were also simulated. The numerical method used in the present wor k is different from that used in previous works and maybe useful in ca se of more complex boundary conditions.