High-speed FBG interrogator based on fiber interferometry and FPGA real-time processing

We present a high-speed fiber Bragg grating interrogator based on an active Sagnac interferometer and phase-generated-carrier demodulation performed in real time by a low-cost FPGA system. The system has 280kHz detection bandwidth and 1MS/s sampling rate, and implements a multitone-mixing scheme to reduce distortion.