Patent ID: 7339680

Claim:
A fiber-optic sensor head for a current or magnetic field sensor, comprising an optical fiber which contains a magnetooptically active sensor fiber and at least one supply fiber which are optically connected, with the sensor fiber having its fiber protective sheath removed, and a capillary in which at least the sensor fiber is arranged, wherein the sensor head can be bent in the area of the sensor fiber, wherein a friction reducing means is provided in the capillary, in order to reduce the friction forces between the sensor fiber and the capillary, and wherein the sensor fiber is a fiber which has not been heat-treated at at least the softening temperature of the sensor fiber material, wherein further the friction reducing means is in the form of a thin friction-reducing layer on the fiber and/or on the inner face of the capillary, and the layers are composed of a dry lubricant or a nanotechnology lubricant comprising a single molecular layer or a small number of molecular layers.