【摘要】 光纤光栅(FBG)的耦合模演化方程经过简单变换转化成Zakharov Shabat系统,该系统的位势参数q(z)与FBG折射率调制函数δneff(z)成正比关系,从而对特定的散射量利用逆散射理论中的Gel′fand Levitan Marchenko(GLM)积分方程求得δneff(z)。进而设计了50GHz零色散FBG方形滤波器,随后将得到的δneff(z)代入耦合模演化方程进行正向求解。计算结果表明,设计的FBG滤波器在所要求的反射谱具有恒定的群时延,同时也具有较好的幅度响应,相邻通道之间的串扰可小于-20dB。更多还原

【Abstract】 The coupled-mode evolution equations of fiber Bragg grating（FBG） were be transformed to Zakharov-Shabat system,whose potential parameter q（z） is proportional to refractive index profile (δn_eff（z）),which then was be obtained by solving the Gel′fand-Levitan-Marchenko（GLM） integration formula of the inverse scattering theory when the scattering parameters are specified.A 50 GHz dispersionless square filter was designed with this method,and the refractive index profile obtained was substituted in the couple-mode equations to carry out direct compute of reflectivity and time delay,computation result showed that the designed filter was the constant time delay in the reflection spectrum and the good amplitude response at the same time,the interaction of adjacent channel can be controlled under -20 dB.更多还原