Linear verification of signal demodulation in fiber nutation tracking system

The performance of fiber nutation tracking system based on coherent demodulation is constrained by the nonlinearity of devices in the signal coherent demodulation module. With the influence of this non-linear factors, the reconstruction accuracy of intensity envelope fluctuation signal depends on the input optical power. The influence of optical amplifiers and detectors on the signal intensity calculation in the range of our interest input optical power is analyzed theoretically and verified experimentally.