INTEGRATED OPTICAL HIGH-VOLTAGE SENSOR USING A Z-CUT LINBO3 CUTOFF MODULATOR

Abstract

An integrated optical ac high-voltage sensor based on a Z-cut LiNbO3 cutoff modulator is fabricated by the proton diffusion method. It is a passive sensor that does not require any electrical bias or any voltage divider. Its sensing voltage range is extended by using the following method: First, its inherent linear range is extended, both by utilizing a novel electrode structure with dummy electrodes and by shortening the electrode length. The dummy electrodes reduce the magnitude of the Z-component electric field applied to the cutoff modulator. Second, a sensor configuration is designed to adjust its operating bias point optically by annealing and thus to utilize the whole extended linear range. The sensing voltage range of the cutoff modulator sensor exceeds ac 1000 V peak to peak.