LIQUID CRYSTAL LIGHT MODULATION DEVICE

摘要

Disclosed is a liquid crystal light modulation device comprising a liquid crystal element consisting of at least one liquid crystal cell and a voltage signal input means . electrically connected with the liquid crystal element, wherein each liquid crystal cell contains a chiral smectic liquid crystal material layer and when a voltage signal is input to the liquid crystal element, the polarization direction of a light transmitted by the liquid crystal element is changed by approx, 90.degree. as compared with the state where the voltage signal is not input to the liquid crystal element. This enables a change of a light path and an open-close (on-off) operation of a light path at a high speed (optical switching time: not longer than 1 msec).