基于长周期光纤光栅的可调谐光滤波器设计

Designing of Tunable Optical Filter Based on Long-period Fiber Grating

分析了长周期光纤光栅(LPFGs)透射谱受外界环境折射率变化影响的特性及其原理,进而提出了一种新型的可调谐光滤波器的设计思路,并运用分段光栅的矩阵分析法对其进行了具体的计算。此种光滤波器具有滤波精度高、可实现滤波波长和深度单独、连续调谐及全光纤性等优点,滤波波长调谐范围可达15nm,衰耗深度调谐范围达9dB。

The characteristic of the change in wavelength of a long-period fiber gratings (LPFGs) attenuation band was analyzed with changes in external index of refraction in detail. Then. based on this characteristic of LPFGs. the designing of a new type of tunable optical filter was put forward. And it was calculated concretely using matrix method of analyzing piecewise-uniform LPFGs. It is concluded that this kind of optical filter has advantages of high precision, independently and continuously tuning of resonance wavelength and peak loss and all-fiber in-line device. The tuning range of filter wavelength reaches 15 nm, and the tuning range of peak loss reaches 9 dB.