A Large Serial Time-Division Multiplexed Fiber Bragg Grating Sensor Network

We demonstrated a wavelength scanning time division multiplexing of 1000 ultra-weak fiber Bragg gratings (FBG) for distributed temperature sensing. The strong multiplexing capability and low crosstalk of the ultra-weak FBG sensors is investigated through both theoretical analysis and experiment. An automated FBG fabrication system was developed for fast 1000-FBG fabrication. The measurement accuracy of Bragg wavelengths for more than 80% FBGs is less than 20 pm, corresponding to 2
$^{\circ}$
C in temperature.