提出了一种基于强度检测的包层模谐振特种光纤传感系统。包层模谐振特种光纤是一种新型的传感元件,对折射率和弯曲等物理量十分敏感。利用它的光谱滤波特性,结合分布式反馈激光器的窄带光谱,可将传感参量改变而引起的光谱移动,最终转化为光强度的变化。在该传感系统中设置了参考光路,抑制了光源波动对实验结果的影响。分析了传感系统中其他影响传感精度的因素。这种方法基于光强度的测量,采用全光设计,无需机械部件调谐,具有方法简单、成本低廉等优点。通过实验,实现了0.0005R.I.U.(单位折射率)的解调精度。
A cladding-mode resonant specialty fiber sensor system is presented by using an intensity detection method. As a new type of fiber-optic sensor technology, the cladding-mode resonant fiber is sensitive to the measurands of the refractive index and bending. Based on the filtering transmission spectrum and narrow band distributed feedback laser, the variation of measurands can be transformed to intensity changes. In the proposed sensor system, a reference arm is added to reduce the affect of laser power fluctuation. The factors that affect the resolution are analyzed. This intensity-based all fiber demodulation technique has the advantages of low cost, simple configuration and requiring no mechanical adjustment. According to the experimental results of the refractive index sensor, a resolution of 0. 0005 R. I.U. (refractive index unit) is achieved.