An Ultra-Fast Demodulation Method of Identical Weak FBG Arrays Based on Multiwavelength RECDFB Laser Array Integrated with SOAs

An ultra-fast identical weak fiber Bragg gratings (wFBGs) demodulation method based on multiwavelength reconstruction-equivalent-chirp distributed feedback (RECDFB) laser array and integrated switching semiconductor optical amplifiers (SOAs) is proposed. The REC technique simplifies the grating manufacturing process of DFB lasers while maintaining excellent single-mode operation. Based on the laser array and the on-chip integrated switching SOAs, the system achieves a cyclic pulsed laser output, and can precisely obtain the location and wavelength information of all identical wFBGs by the reflection spectra within each cycle. This system realizes an ultrafast wavelength demodulation rate at 125 kHz which greatly enhancing the demodulation speed of TDM sensing networks. Experimental results show that the system demodulation error over 500 consecutive cycles is less than 5 pm.