[22p-D215-1~10] 3.14 Optical control devices and optical fibers

[22p-D215-6] Wavelength-division multiplexed sensing of fiber Bragg gratings using a distributed-feedback laser array

〇Keiji Kuroda¹ (1.Kitasato Univ.)

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

I report WDM interrogation of multiple FBGs. The heterodyne detection technique is used to increase the signal-to-noise ratio. A directly modulated DFB laser array is used as a three-wavelength, frequency scanning, pulsed-light source. Weak reflections from three FBGs are recorded as beat signals with a high signal-to-noise ratio using heterodyne detection. Reflection spectra are clearly observed from the three different-wavelength FBGs with a reflectivity of 1% and a spatial interval of approximately 1.5 m.