长周期光纤光栅谐振波漂移规律研究

为了研究长周期光纤光栅纤芯、包层半径及折射率改变时光栅有效折射率和耦合系数的变化规律,采用理论分析与数值模拟相结合的方法,总结出长周期光纤光栅结构参量与透射谱谐振波漂移的关系。结果表明,当光纤结构参量a1,a2,n1和n2增大时,谐振波向短波方向漂移,仅当周期Λ增大时,谐振波才向长波方向漂移。这一结果对设计长周期光纤光栅是有帮助的。

Study on the excursion rule of resonance waves of long period fiber gratings

In order to study the dependence of the effective index and the coupling constant on the radii and refractive index of the fiber core and cladding, the relation between the structural parameters and the change of the resonance wave of the transmission spectra was obtained by means of theoretical analysis and the numerical simulation. The results show when the radii a1,a2 and refractive index of fiber core and cladding n1, n2 increase, the resonance wavelengths shift towards shorter wavelengths; when the grating period Λ increases, the resonance wavelengths shift towards longer wavelengths. The conclusion can be used for reference in the design of long period fiber gratings.