光纤F-P传感器偏振互相关解调中光楔参数的影响研究

Birefringent wedges effects on cross-correlation polarization demodulation in optical fiber Fabry-Pérot sensors

对光纤法布里-珀罗(F-P)腔长偏振互相关解调法中的双折射光楔进行了理论和实验研究,建立了双折射光楔对干涉光程差影响的数学模型,并进行了数值仿真。仿真结果表明,当楔角为4°时,要保证楔面内任意点处的光程误差在15nm以内,入射角应小于0.3°,光楔光轴倾斜应小于0.8°,楔面垂直度误差应小于0.15°。采用光楔进行了偏振光干涉实验,实验干涉条纹与理论条纹基本一致,实验干涉条纹的倾斜度与理论倾斜度相差0.02°。

The effects of the birefringent wedges in the cross-correlation polarization demodulation system of optical fiber Fabry-Pérot sensors are analyzed.A mathematical model for the optical path difference is established based on the results of the incident angle,optical axis and oblique of the wedge surface.The error of the optical path difference between the theoretical model and the simple model is simulated.The analysis results indicate that the error of the simple model for optical wedges is less than 15 nm only if the incident angle is less than 0.3°,and the optical axis is less than 0.8°and the vertical error of the wedge surface is less than 0.15°,when the wedge angle is 4°.The fringes of the experiment based on polarized light interference with the birefringent wedge are mostly consistent with the theoretical fringes.The slope difference between the experimental fringes and the theoretical fringes is 0.02°.