| 摘要 |
PROBLEM TO BE SOLVED: To provide an interference type optical fiber sensor that is able to broaden a frequency band used for demodulation, by tracking a change in the phase of a sensing signal even when the change is fast.SOLUTION: An interference type optical fiber sensor 1 comprises: a light source part 11; a detecting part 21 configured to output a plurality rays of phase-modulated pulse light such that a pulse strings are time-shifted from one another two or more times; and a light receiving element that outputs a pulse waveform on the basis of a pulse string. The light source part 11 includes a pulse light source 31 that extracts continuous light in a predetermined sampling period, thereby outputting a single ray of pulse light; and a feedback circuit that provides feedback for a single ray of pulse light a predetermined number of times, and outputs rays of pulse light. The number of times that feedback is provided is adjusted for each of the feedback circuits, and the respective pulse light periods of rays of pulse light are set to an interval shorter than the sampling period. |
