| 摘要 |
A twisted ferroelectric liquid-crystal optical modulator in which a ferroelectri c smectic C* liquid crystal (26) is filled into the gap between two alignment layers (18, 20) aligning the adjacent liquid cryst al in two perpendicular directions parallel to the alignment layers. The ferroelectric liquid crystal has a tilt angle of 45.degre e. and is aligned with the tilt angle parallel to the buffing direction of the alignment layer. Thereby, the liquid-crystal molecules (32), a bsent any applied field from electrodes (14, 18), slowly twists through 90.degree. across the gap, and the liquid crystal waveguides ligh t linearly polarized by an input polarizer (22) so that it passes a perpendicularly arranged output polarizer (24). However, a strong elec tric field causes the ferroelectric molecules to untwist and line up in parallel, thereby destroying waveguiding, and the cell do es not transmit. Intermediate voltages cause partial untwisting and partial waveguiding. Thus, variations in the applied voltages ca n modulate the light according to a gray scale.
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