POLARIZATION SURFACE PRESERVING OPTICAL FIBER TYPE MAGNETIC FIELD SENSOR

摘要

PURPOSE:To enable measurement in a high temp. atmosphere without using a polarizer and an analyser, by fixing the end surface polarizing axes of polarization surface preserving optical fibers opposed to each other so as to hold a Faraday rotary element therebetween in a mutually 45 deg. shifted state. CONSTITUTION:Laser beam from a light source 1 is projected into a Faraday rotary element 106 through a converging lens 102, a beam sending side polarization surface preserving optical fiber 103 and a collimator 104 while the linear polarizability thereof is enhanced by a polarizer 105. The emitted beam from the element 106 is received by a light receiver 108, a condensing lens 102', a polarization surface preserving optical fiber 103' fixed so as to incline the polarizing axis 45 deg. with respect to the polarization surface of the emitted light of the element 106 in the case of no-magnetic field, a collimator 104' or the like. Therefore, it is unnecessary to provide a polarizer or an analyser resulting in characteristic deterioration at a high temp. in the vicinity of the Faraday rotary element and, because the polarizing axes in front of and rear to the Farday rotary element are mutually inclined by 45 deg., magnetic field measurement can be performed in high preciseness at a high temp.