Study on Phase Noise Characteristics of Optical Fiber Sensing System Based on Remotely Pumped Light Amplification

Remotely Optically Pumped Amplifier is an important form of the interference type optical fiber sensing remote relay transmission system. In this paper, the relationship between the nonlinear spontaneous Raman effect and the sensor phase noise in remotely pumped optical amplification is studied. The results show that in a 100km transmission system, with the increase of pump power the spontaneous Raman effect increases and a random fluctuation of pump optical power. The pump light fluctuation leads to the gain distortion and decrease of the remote gain unit, which ultimately transforms the pump intensity noise into the phase noise of the system. The experimental results show that when the pump power is controlled below 1.1W, the phase noise of the remotely pumped optical amplification system is at - 98dB@1kHz. And there are no obvious phase noise introduced into the remotely pump optical amplification system.