基于啁啾相移光纤光栅的滤波器设计及应用

相移光纤光栅作为透射型带通滤波器件降低了使用成本和插入损耗.在光通信和传感领域有着较高的应用价值.啁啾相移光纤光栅的透射峰波长和数量由相移点的位置和数量来确定,透射峰特性受相移量的影响.采用分段切趾的方法获得满足光通信要求的滤波特性,利用传输矩阵法分析了切趾前后透射峰特性的变化,结果表明:切趾改善了滤波器的幅度和相位响应,依据滤波器的设计要求选取不同的切趾函数以及切趾比例;切趾还大大减弱了透射峰波长和深度对相移量的敏感度,适当切趾后相移量的影响可以忽略.并提出一种应用双通道啁啾相移光纤光栅滤波器产生脉冲毫米波副载波信号的方案.

Design and Application of Optical Filters Based on Chirped Phase-Shifted Fiber Gratings

As a transmission type filter, phase-shifted fiber grating has the advantage of low cost and low additional loss, and it is a critical component in optical communication and sensor systems. As for chirped phase-shifted fiber gratings, the transmission peak wavelength and number are determined by the position and number of phase shift and the characteristics of the transmission peak are significantly affected by the amount of phase shift. Sectional apodization is used on chirped phase-shifted grating to obtain appropriate filtering properties for optical communication. The transmission peak characteristics are theoretically analyzed by transfer matrix method for chirped phase-shifted gratings with and without apodization. The numerical results show that the amplitude and phase response of the filter are improved and design requirements can be satisfied by proper apodization function and ratio. Meanwhile, the dependence of the transmission peak wavelength and depth on phase shift is diminished greatly and the impact of phase shift can be ignored by proper apodization. A method is proposed to generate millimeter subcarrier optical signal by using a double-channel chirped phase-shifted grating filter.