OPTICAL FIBER CURRENT SENSOR CONCERNED WITH REDUCING VOLUME THEREOF BY USING LONG PERIOD OPTICAL FIBER GRATING PRODUCED ON POLARIZATION MAINTAINING OPTICAL FIBER

摘要

PURPOSE: An optical fiber current sensor is provided to reduce the volume of a current sensor and costs by using a long period optical fiber grating produced on a polarization maintaining optical fiber, rather than a bulk type analyzer. CONSTITUTION: An optical fiber current sensor comprises an input unit, a measurement unit, and an analyzing unit. The input unit for providing an input light source for the current sensor, includes a light source(11) and a polarization controller(12). The measurement unit includes a sensor head(13) for an optical fiber coil. The analyzing unit converts the intensity of the current into an intensity of light source, and displaying the result. The measurement unit includes a single mode optical fiber(10) having a cutoff frequency for guiding the output of the light source of the input unit in a single mode. The analyzing unit includes an analyzer for converting changes of polarized light into an intensity of light, a photo-detector(15) for converting the intensity of light into an electrical signal; and an oscilloscope(16) for displaying the electrical signal outputted from the photo-detector.