[17p-P03-1~5] 3.14 Optical control devices and optical fibers

[17p-P03-5] Application of heterodyne detection using a DFB laser to FBG sensor

〇Keiji Kuroda¹, Akari Hirai¹, Chanq Xin Rin² (1.Kitasato Univ., 2.Tokyo Inst. of Tech.)

Keywords:Fiber Bragg grating sensor, Heterodyne detection, DFB laser

We report on application of a heterodyne detection technique using a frequency scanning pulse trains to increase a sensitivity of FBG (Fiber Bragg Grating) sensor. A detection sensitivity of reflection from a FBG is increased about 30 dB compared to the direct detection using a heterodyne detection technique and a balanced detector. It is shown that a distance to FBG can be expanded to 20 km by applying interference between different pulses.