PHOTOMAGNETIC FIELD SENSOR

• Main Author: TOBA YOSHIKAZU
• Format: Patent
• Language: English
• Published: 29.06.1992
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

PURPOSE:To enhance the stability of the output of a sensor by providing plano- convex lenses at both ends on the light path of an analyzer. CONSTITUTION:The light 26 emitted into a case from a collimator lens 20 is determined in its polarization direction by a polarizer 14 and bent by 90 deg. to be incident on a Faraday effect element 16. The polarized light other than that in the polarization direction advances straightly. The incident light receives modulation in proportion to the intensity of an applied magnetic field H. The light expanded by the optical diffraction due to the magnetic domain generated when light is incident on the Faraday effect element 16 is converted to parallel light by a plano-convex lens 17 and converted in its direction by 90 deg. by a total reflection mirror 19 to be incident on an analyzer 15. The analyzed parallel light is condensed by a plano-convex lens 18 to become emitted light 27 which is, in turn, incident on the photodetector provided on the outside of the case through an optical fiber 24 to be photoelectrically converted and the intensity of the applied magnetic field H due to photoelectric conversion is detected. By this method, the stability of the output of a sensor can be enhanced.