高速大容量光纤光栅解调仪的研究

Research of High-Speed Large-Capacity Fiber Bragg Grating Demodulator

采用半导体光放大器和可调谐法布里-珀罗滤波器,以环路结构组成高速扫描激光器,结合光耦合器、光环路器和光电二极管等,形成4通道大容量高速光纤光栅解调仪。系统采用2kHz的类三角波调制信号,驱动法布里-珀罗滤波器在50nm的光谱范围内进行快速扫描。通过引入光纤梳状滤波器和单峰滤波器组成的参考通路,消除法布里-珀罗滤波器的非线性效应和扫描波长漂移问题,使得解调仪具有很好的稳定性和线性度。高速光纤光栅解调仪的稳定性为2pm,分辨率为1pm,线性度为0.99957,测量精度为5pm,解调频率为2kHz。

A four-channel large-capacity, high-speed fiber Bragg grating demodulator is proposed. It constitutes of semiconductor optical amplifier and tunable Fabry-P6rot filter which is composed a high-speed scan laser in a loop structure, combining the optical coupler, optical loop circuit and photodiode. A 2 kHz triangular-like modulation signal is used in this system to drive the Fabry-P6rot filter to make fast scan in the range of 50 rim. The nonlinear effect and scan wavelength shift can be eliminated in Fabry-P6rot filter by introducing the reference channel composed by optical fiber comb filter and single-peak filter, leading to the excellent stability and linearity of demodulator. The stability of high-speed fiber Bragg grating demodulator is 2 pm; the resolution is 1 pm; the linearity is 0. 99957; the measuring accuracy is 5 pm, the demodulation frequency is 2 kHz.