OPTICAL FIBER RING INTERFERENCE TYPE SENSOR AND METHOD FOR CORRECTING FLUCTUATIONS IN INTERFERENCE LIGHT INTENSITY

摘要

PROBLEM TO BE SOLVED: To provide an optical fiber interference type sensor which allows to calculate a phase difference with high precision by performing correction using a predetermined maximum value and a minimum value even when there are fluctuations in interference light intensity or the output of an amplifier circuit.;SOLUTION: The optical fiber interference type sensor comprises an amplification means for amplifying a light signal received by a light receiving element, a level fluctuations amount decision means for monitoring fluctuations in a signal level outputted from the amplification circuit within a predetermined range of time including the initial state, a vibrationless decision means for monitoring whether the fluctuations in the signal level has exceeded a standard level or not, and a correction calculation means for calculating a light level fluctuations correction value by acquiring a voltage level value calculated by a level signal decision means when the signal level is the standard level or less. The phase difference can be thereby calculated, allowing to calculate the phase difference with high precision even when there are fluctuations in the interference light intensity or the output of the amplification circuit.;COPYRIGHT: (C)2006,JPO&NCIPI