초록 ▼

An apparatus of measuring an electric signal comprises a laser device, optical elements, an electrooptic crystal, a photoelectric converter, and an electric circuit. The electrooptic crystal is selected from the materials in the type of having properties of changing its refractive index in the direc

An apparatus of measuring an electric signal comprises a laser device, optical elements, an electrooptic crystal, a photoelectric converter, and an electric circuit. The electrooptic crystal is selected from the materials in the type of having properties of changing its refractive index in the direction of its optic major axes and the direction of these axes by a function of an applied electric field. In the apparatus, the electrooptic crystal is placed in the electric field applied by an electric circuit under measurement. A laser beam emitted from the laser device is incident on the electrooptic crystal. A reflected light passed through the crystal is resolved into rays in two polarized direction. Each ray is subjected to a photoelectric conversion by passing through the photoelectric converter and exerted as an electric output. A differential signal of the electric output is defined as a measurement signal. By selecting two polarized directions of the laser beam by a half-wave plate as the optical element, two signals corresponding to the changes in the refractive index and optic major axes of the crystal. Two component of a vector of the electric field can be obtained by a first order combination of these signals.

대표청구항 ▼

[ What is claimed is:] [1.] A method of electro-optical measurement for vector components of an electric field by a detection of a potential between two points in an electric circuit or an electric field generated by said electric circuit, in which variations in optical characteristics of an electro

[ What is claimed is:] [1.] A method of electro-optical measurement for vector components of an electric field by a detection of a potential between two points in an electric circuit or an electric field generated by said electric circuit, in which variations in optical characteristics of an electrooptic crystal adjacent to said electric circuit are used for said detection, said method comprising steps of:introducing an optical pulse having a predetermined polarized condition as an incident light into said electrooptic crystal in a direction parallel to one of optic major axes of said electrooptic crystal under a condition that an electric field is not applied on said electrooptic crystal;modulating said predetermined polarized condition of said incident light into two different polarized conditions by passing said incident light through a half-wave plate and a polarizer without mechanically displacing said electrooptic crystal;converting optical outputs from said electrooptic crystal into electric signals with respect to said two different polarized conditions, respectively;measuring magnitudes of said electric signals, respectively; anddetermining two of three components of a vector of said electric field in said electrooptic crystal by performing an arithmetic operation on results of said measurement.