DISTRIBUTION TYPE OPTICAL FIBER SENSOR AND A METHOD FOR CONTROLLING BEAT NOISE OF THE DISTRIBUTION TYPE OPTICAL FIBER SENSOR, CAPABLE OF AVOIDING THE DISTORTION OF A BRILLOUIN GAIN SPECTRUM CAUSED BY THE BEAT NOISE BY CONTROLLING THE BEAT NOISE

摘要

PURPOSE: A distribution type optical fiber sensor and a method for controlling beat noise of the distribution type optical fiber sensor are provided to measure physical changes and the temperature of a large building, a bridge, an aircraft, and a railway vehicle by using a brillouin optical correlation domain analysis.;CONSTITUTION: A distribution type optical fiber sensor comprises a test optical fiber(30), a light source unit(10), a light modulation unit(20), and an optical detecting unit(50). The light source unit outputs lights modulated into a first frequency. The light modulation unit generates first optical signals including sideband signals and second optical signals chirped into a second frequency having a preset ratio with respect to the first frequency by utilizing the light emitted by the light source unit and applies the first and second optical signals respectively to both ends of the test optical fiber. The optical detecting unit detects brillouin scattered light generated by the first and second optical signals from the test optical fiber.;COPYRIGHT KIPO 2013;[Reference numerals] (210) Light distributor; (225) Signal generator; (530) Phase lock amplifier; (AA) Probe; (BB) Pump