A 2*2 fiber optic switch using chiral liquid crystals

Abstract
A nonchemical 2*2 optical switch for fiber optic applications is described. Using a chiral-nematic liquid-crystal cell and switchable nematic liquid-crystal waveplates, the authors measured -26-dB crosstalk between unselected fibers, a fiber-to-fiber insertion losses of 1.4 dB, and switching times under 40 ms with operation at 1318 nm using 62.5/125- mu m multimode fiber. The device features simple construction, low power requirements, and an optical bandwidth suitable for LED or laser sources, and it works equally well with multimode or single-mode fiber.