采用光纤布拉格光栅(FBG)传感系统研究压电陶瓷(PZT)驱动法布里-珀罗(F-P)型可调谐光滤波器(TOF)的非线性特性。基于多光束干涉理论建立了TOF的非线性模型,推导了透射带波长和自由光谱范围(FSR)对驱动电压的非线性响应;基于FBG传感系统测试了F-P型TOF的波长非线性,并采用多项式拟合对其进行描述,实测F-P型TOF波长的非线性误差最大为1.006 nm;基于F-P型TOF的非线性模型,研究了其波长定位误差,并提出采用参考光栅的方法降低波长定位误差。实验表明,F-P型TOF的波长随机误差可由73~81 pm降至12 pm以下。
The nonlinearity of Fabry-Perot(F-P) type tunable optical filter(TOF) driven by piezo-electrical transducer(PZT) is investigated using fiber Bragg grating(FBG) optical fiber sensing system.The nonlinearity of the TOF is modeled based on multiple-beam interference theory.And the respondences of the transmission wavelength and free spectrum range(FSR) on the drive voltage are deduced from the model.The nonlinearity of the TOF is measured using FBG sensing system.And polynomial fit is adopted to describe the nonlinearity characteristic.The maximum error of the TOF deduced by the nonlinearity is measured as 1.006 nm experimentally.Based on the model,the random wavelength error of the TOF is researched at the same time.And the reference grating is proposed to reduce the random wavelength error in other ranges.It is illustrated that the random wavelength error of the TOF can be decreased from 73 pm-81 pm to below 12 pm.