Optical wavelength measuring device using absorption-type optical fiber-based multiple optical fiber filter module, optical sensor system having the same, and optical measurement method

An optical fiber sensor system comprising:

• a light source outputting input light;
• an optical fiber sensor installed in a measurement target, and receiving the input light from the light source and outputting signal light corresponding to a physical quantity change by the measurement target;
• and
• an optical wavelength measuring device detecting the signal light output from the optical fiber sensor and calculating a physical quantity applied to the optical fiber sensor,
• wherein the optical wavelength measuring device includes
• a first optical splitter splitting the signal light provided from the optical fiber sensor into first and second split lights,
• a first optical detection unit detecting the first split light output from the first optical splitter,
• a polarization controller installed on an optical path of the second split light output from the first optical splitter, and controlling a polarization state of the second split light,
• a second optical detection unit detecting the second split light which is polarization-controlled by the polarization controller, and
• a calculation module calculating an optical wavelength of the signal light according to a physical quantity applied to the optical fiber sensor based on information detected by the first and second optical detection units.

An optical measurement method comprising:

• an input light outputting step of outputting, by a light source, input light to an optical fiber sensor installed in a measurement target;
• a first light splitting step of receiving the signal light output to correspond to the physical quantity applied to the optical fiber sensor, and splitting the signal light into first and second split lights by using a first optical splitter;
• a first light receiving step of detecting the first split light split in the first light splitting step;
• a polarization control step of controlling a polarization state of the second split light split in the first light splitting step by using a polarization controller;
• a second light receiving step of detecting the second split light after the polarization control step;
• and
• a wavelength and physical quantity calculating step of finally calculating the physical quantity applied to the optical fiber sensor by calculating the optical wavelength of the signal light based on the detection information detected in the first and second light receiving steps.