16-Channel Fiber Laser Sensing System Based on Phase Generated Carrier Algorithm

A 16-channel fiber laser sensing system based on four wavelength and four space division multiplexing and phase generated carrier (PGC) algorithm is proposed. Through introducing dc block and normalization technology, the influence of light intensity and fringe visibility is decreased. A point-by-point calculation is adopted during PGC processing and we realized 16 channels real-time synchronous demodulation with high performance and stability based on PC and LabView. The wavelength shift resolution of the system is 6×10^-7 pm/√Hz, the linearity is , and the dynamic range is 115 dB at 10 Hz and 98 dB at 100 Hz. For multichannel demodulation, the amplitude consistency is and crosstalk less than -60 dB has been obtained; the correlation coefficient between the real signal and demodulated signal is .