Optical modulator

Abstract

Abstract PURPOSE:To vary the transmittivity of an optical switch by giving a DC bias to an AC voltage applied to a liquid crystal cell, and controlling the DC bias. CONSTITUTION:A scanning electrode 4 is used as a common electrode, an AC voltage is applied uniformly between an auxiliary electrode 2 and the scanning electrode 4 by an AC voltage power source 9, and a DC voltage is applied through a resistance R10 to an arbitrary one in an electrode group being a signal electrode 5 which is brought to wiring in a stripe shape, and is formed by an ITO film. In order that an AC bias electric field is applied effectively, it is desirable that 100kOMEGA-10MOMEGA is connected as R, and when only the AC voltage is applied, a liquid crystal cell becomes turbid in white, and the transmittivity becomes minimum. In this state, when a prescribed DC bias is given to an intersection part of the selected scanning electrode 4 and the signal electrode 5, the transparency of its intersection part increases, and the transmittivity increases. In such a way, by bringing the DC bias to a variable control by a variable DC power source 8, the transmittivity of an optical switch can be changed.

Inventors

• 👤 Fumitaka Kan
• 👤 Naoji Hayakawa

Bibliographic Details