基于VSLMS算法的标本化FBG的相位结构的控制

Identification of the Phase Structure of Sampled FBG Based on VSLMS Algorithm

利用标本化光纤光栅(SFBG)设计实现的横向滤波器能够任意地实现各种光信号处理,但在制作SFBG过程中的相位误差问题会直接影响到滤波器的性能。因此,应用变步长最小均方算法(VSLMS)对存在相位误差的SFBG进行解析,提出利用在相邻FBG之间用紫外光照射改变光纤纤芯屈折率,进而控制SFBG的相位误差。研究通过实验测得了UV脉冲数与相位修正量的关系,利用该测量结果即可实现制作SFBG时对相邻子FBG间的相位的精确控制。

A transversal filter based on sampled FBG （SFBG） can realize various optical signal processing freely. However, the phase error appeared during the fabrication process will directly affect the performance of the filter. In order to control the phase error in SFBG, the variable step least mean square algorithm （VSLMS） is applied in this paper to analyze the SFBG that has phase error, and a method by using UV irradiation to change the refractive index of fiber core is proposed. The relevance of the number of UV irradiation and phase correction is achieved by experiment, and the accuracy phase error controlling can be realized according to the experiment result.