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Laser Power Reduction In Liquid Crystal Device

IP.com Disclosure Number: IPCOM000049074D
Original Publication Date: 1982-May-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Yang, KH: AUTHOR

Abstract

In thermally activated smectic liquid crystal devices an important parameter is the energy required to generate a scattering center in the liquid crystal. It is known that certain impurities present in the liquid crystal can enhance the scattering center formation, thus reducing the laser writing energy of the device.

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Laser Power Reduction In Liquid Crystal Device

In thermally activated smectic liquid crystal devices an important parameter is the energy required to generate a scattering center in the liquid crystal. It is known that certain impurities present in the liquid crystal can enhance the scattering center formation, thus reducing the laser writing energy of the device.

The device described herein reduces the writing energy of a laser beam in a liquid crystal device by strain-enhanced scattering center formation in the liquid crystal. Fig. 1 depicts a configuration for generating a static strain in the liquid crystal cell by two rows of clamping and pushing screws incorporated at the edges of the cell. By properly adjusting the screws, a static strain is induced in the liquid crystal which enhances the scattering center formation when the device is subjected to laser writing. Consequently the required laser power is reduced.

Alternatively, a dynamical strain wave can be generated in the liquid crystal by piezoelectric transducers attached on the edges of the liquid crystal cell as depicted in Fig. 2. One to four transducers can be used on the four edges on the cell. Typical transducer materials are quartz crystal, ammonium dihydrogen phosphate (ADP), potassium dihydrogen phosphate (KDP), and ferroelectric ceramics such as BaTiO(3). The existence of the strain wave in the liquid crystal will reduce the laser power required to thermally address the cell.

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