JPS643632A - Method and element for optical modulation - Google Patents

Abstract

PURPOSE:To execute good initial orientation by interposing a liquid crystal compsn. contg. a ferroelectric liquid crystal which is in the state of a smectic A phase between electrodes or magnetic poles facing each other and changing the tilt angle of the ferroelectric liquid crystal induced by an external field such a electric field or magnetic field. CONSTITUTION:The ferroelectric liquid crystal 5 is interposed between two sheets of transparent substrates 2 with electrodes facing each other and is held between two sheets of polarizing plates 1 intersecting orthogonally with each other. The orientation direction of the major axis of the molecules changes and optical switching is executed if the ferroelectric liquid crystal 5 is maintained in the smectic A phase state by changing the temp. and the electric field is impressed thereto. Namely, the good initial orientation is obtd. if unaxial orientation control is executed in the case of executing optical switching with the smectic A phase. The switching equal to each other is executable even if the positive and negative electric fields are impressed. The simple initial orientation is thereby enabled and in addition, high strength to mechanical impact and gradation characteristic are provided to the orientation condition without requiring extremely thin films.