A small number of bifunctional monomers are mixed with a nematic liquid crystal (LC) and cured with a distributed electric field, which is produced by a circular-hole-patterned electrode structure. A gradient type of lens, that is, a LC microlens, is investigated for various polymer concentrations. Addition of 3% polymer is enough to freeze the gradient-index properties of the structure in the form of a convex lens, and a polymer-stabilized LC microlens is demonstrated. Although a lower concentration of polymer cannot hold the distribution properties in a curing process, it can maintain the variable focus as a nematic material can. The polymer networks can also eliminate the disclination line that usually appears and causes the lens in this type of LC device to deteriorate.
© 1997 Optical Society of America
Toshiaki Nose, Shin Masuda, Susumu Sato, Jianlin Li, Liang-Chy Chien, and Philip James Bos, "Effects of low polymer content in a liquid-crystal microlens," Opt. Lett. 22, 351-353 (1997)