FIBRE OPTIC SENSING ELEMENT OF ELECTRIC CURRENT AND MAGNETIC FIELD SENSOR Russian patent published in 2023 - IPC G01R19/15 G01R33/32 

FIELD: fibre optics.

SUBSTANCE: fibre optics, in particular fibre optic current and magnetic field sensors. Sensing element of a fibre-optic sensor of electric current and magnetic field, including an optical fibre with a helical structure of built-in linear birefringence (BBR), consists of two parts, the first and second parts are made of fibres with a helical structure of built-in linear birefringence with different values of the Verdet constant of light-guiding core materials, or the Verdet constant of sheath materials, or strand sizes, or core-to-sheath refractive index ratios, or built-in linear BBR, or BBR helical pitch, or a combination of these parameters, one fibre part is located along the other part and the parts are optically interconnected on one side. As a result, the Faraday phase shifts induced by the current magnetic field in the fibre parts of the sensing element have different values and are subtracted. To achieve the optimum effect, the fibres of both parts of the sensing element must be closed. In this case, the difference in the parameters of both fibres is determined by the required value of the maximum measured current.

EFFECT: implementation of the claimed solution is the manufacture of a sensitive element of the electric current and magnetic field sensor with reduced sensitivity, which is necessary to create sensors designed to measure currents up to several tens of megaamperes or more.

4 cl, 2 dwg