Electro-optical voltage measurement device

Abstract

A device for electro-optically measuring a voltage in a high-voltage conductor, which voltage will produce an electrical field that will elliptically polarize both a linearly polarized light beam or a circularly polarized light beam, the device having a transmitter providing a source of light as a light beam, polarizer for the light beam, a head section at the high-voltage conductor and a receiver on a base which is spaced from the head section, said receiver having a device for measuring the voltage due to a phase difference between the components of the light beams passing with different transit speeds, characterized by the transmitter being on the base, a supply line extending from the source to the head and at least one return line for conducting the light beam having a desired polarization, which is either linear or circular, between the head section and the base, at least one of the lines being formed by a crystal fiber with a longitudinal, linear electro-optical effect and consisting of a piezoelectric material which becomes birefringent in an electrical field. The supply and return lines may be of the same or different electro-optical material with the different materials selected to compensate for temperature induce birefringence. Also only one line need to be of the electro-optical material.