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Improved NLO properties through a liquid crystal phase poling
Author(s) -
Lee JaeSuk,
Cho YoungSun,
Cho Gyoujin,
Jung Kyeong Taek,
Shul Yong Gun
Publication year - 1997
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690431330
Subject(s) - poling , chromophore , liquid crystal , materials science , mesogen , phase (matter) , thermal stability , absorption (acoustics) , composite material , organic chemistry , chemistry , ferroelectricity , optoelectronics , liquid crystalline , dielectric
Cross‐linkable organic NLO chromophore called DRS was chemically incorporated into silica matrices using the sol–gel process. A number of electrically poled DRS/silica matrix systems were studied to elucidate the relaxation of the oriented organic chromophore by following the decay of UV absorption as a function of time and temperatures. The value of the second harmonic coefficient d 33 was 47 pm/V for the DRS/silica matrix films (0.4 μm thickness). From the dramatic decrease in the UV absorption after poling at 80°C, it is speculated that the DRS may act as a liquid crystalline mesogenic group and is effectively oriented in poling at the phase (nematic) transition temperature (80°C). This argument was substantiated by investigating the phase behavior of DRS itself using both DSC and a polarized optical microscope. The DRS/silica system contained the ideal matrices to retain the oriented chromophore because of optical clarity, thermal stability and effective poling at the nematic liquid crystalline phase.