A long-distance FBG sensor system based on LPFG denoising and hybrid amplification

作者：Wu Min^*; Rao Yun Jiang; Ran Zeng Ling; Xie Kong Li

来源：Journal of Optoelectronics - Laser, 2007, 18(11): 1289-1292.

• Er doped fiber (EDF)
• Fiber Bragg grating (FBG) sensor
• Long distance sensing
• Long period fiber grating (LPFG)

The designed long distance fiber Bragg grating (FBG) sensor system based on long period fiber grating (LPFG) and Er-doped fiber (EDF)/Raman hybrid amplification optimizes the signal-oisc ratio (SNR) and promotes sensing distance to 50 km. Such a system employs a powerful swept laser as the light source and demodulation system. By adding LPFG. the amplified spontaneous emission (ASE) noise of bidirectional Raman amplification and FBG backward reflective noise are reduced. Meanwhile, by utilizing left pump power, the dual circulators EDF structure is used for ASE light generation to illuminate the back-located FBG sensors and amplify the sensor signals to improve their SNR. Compared with EDF/Raman hybrid amplification, the hybrid amplification with LPFG achieves that 4.40 dB and 4.38 dB SNR are increased for FBG 1 and FBG 2 respectively, and over 15 dB SNR is achieved for four FBG sensors distributed along 50 km.

• 出版日期2007