27 August 2008 Liquid crystal based electro-optic Bragg gratings for laser beam attenuations
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This paper provides research progress in the development of fast electro-optic gratings based on liquid crystals for laser beam attenuations. The electro-optic phase grating is formed by the phase separation of ~100nm liquid crystals droplets from a polymerizing organic matrix using holographic interference technique. The formed grating separates the incident laser beam into the output beams: the transmitted and diffracted beam, whose intensities can be electrically adjusted through electro-optic effect. The fast electro-optic gratings have a very fast electro-optic response time of 50 microseconds with diffraction efficiency above 99.8%. Optical receivers used in FSO have a limited dynamic range and there is a need for in-line variable attenuators to keep the signal levels from overloading the receiver. These attenuators should be continuous, provide sufficient attenuation, and also provide a low insertion loss for weak signal reception. The use of electro-optic Bragg gratings is one solution to meet the requirements for an in-line attenuator for FSO.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
James Foshee, James Foshee, Brian Stadler, Brian Stadler, Suning Tang, Suning Tang, Yuanji Tang, Yuanji Tang, Jennifer Colegrove, Jennifer Colegrove, } "Liquid crystal based electro-optic Bragg gratings for laser beam attenuations", Proc. SPIE 7050, Liquid Crystals XII, 70500W (27 August 2008); doi: 10.1117/12.796208; https://doi.org/10.1117/12.796208

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