Device corona poling

Fabry-Perot etalon devices based on materials sensitive to electric fields have been studied as tuneable optical filters. Gan et al. [165] presented in their work a hybrid organic/inorganic sol-gel material based on 3-methacryloxypropyl trimethoxysilane as precursor and TCBD (15% mol) as NLO chromophore that was covalently incorporated into the silica network. They demonstrated an optical filter having large tunability and high finesse. The EO sol-gel film was corona poled with 5 kV/cm at 170°C for 30 min. 

Surface voltage decay was measured with a Trek Model 341 high voltage electrostatic voltmeter (ESVM). The ESVM drives the potential of a probe body to the same potential as the film surface voltage. This device measures the voltage independent of distance within 5 mm of the film surface without causing current flow, which would modify the data. After poling, the corona needle was removed and the probe of the ESVM was placed 3 mm from the film surface. 

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