In-Line Sagnac Interferometer-Type Optical Voltage Sensor For Dc Voltage Measurement

In-line Sagnac Interferometer-type optical voltage sensor for DC voltage measurement was proposed. The high input resistance of pockel's cell contributes to the miniaturization of a sensor size and realizes highly precise measurement. The problem of DC voltage measurement was offset drift of signal processor. To solve the problem, in-line Sagnac interferometer which used in DC current sensor has been applied. Input-output characteristics and long term stability within 3 days has been confirmed. These results show that the stabilities of the optical voltage sensor are within +/- 0.5%.