新型多模光纤光栅特性的研究

提出了一种单轴各向异性材料为包层,主轴折射率沿光栅轴线(Z轴)方向的新型多模光纤光栅模型,引入主轴折射率比参数Kcl,运用耦合模理论等方法,对此类光纤光栅的反射特性进行研究,并着重讨论了数值孔径NA与主轴折射率比参数Kcl对多模光纤光栅中低阶模式特性参数的影响。研究结果为传感、测量等领域获得新的应用提供了理论依据,可以用多模光纤光栅代替单模光纤光栅制作光纤传感器以降低成本,也可作为对光纤光栅进一步深入研究的参考。

Study on characteristics of a new multimode fiber grating

A new multimode fiber grating with cladding made of uniaxial crystal material whose optical axis is paralled to the axis of fiber Bragg gratings was proposed.The ratio(Kcl) of the ordinary ray index was introduced.By using the coupled-mode theory,the characteristics of such fiber grating reflection are studied,and these characteristic parameters were dependent on the parameter Kcl and NA.The applications of such multimode fiber Bragg grating in optical communication,especially in optics sensors were predicted.The studies provide an important basis for further analyzing fiber Bragg grating characteristics for designing new optical apparatus in communication and sensors.That is,the multimode fiber grating may replace single-mode fiber grating to produce fiber sensors.The experimental results also provide guidance for further studying on multimode fiber Bragg gratings.