提出了一种基于Michelson Gires-Tournois interferometer(MGTI)型不等带宽光交错复用器(interleaver)的新颖设计方法,可以简便地得到所有结构参数。通过z变换简化多镜GT腔(GTE)复杂的透射方向和反射方向光波电矢量的表达式,结合数字信号滤波器中椭圆滤波器的设计原理,利用极点值即可得到GT腔的腔长、臂长差和GT腔各镜面的反射率。给出了占空比为1:3的25 GHz不等带宽interleaver的设计实例,比较了采用不同GT腔结构的多组模拟仿真结果。分析了实现任意占空比interleaver的设计原理,给出了同一3阶结构情况下的4组不同占空比的设计实例,以及3组不同阶数下的占空比为1:4的该结构光交错滤波器的具体设计参数和结果。
A novel method for designing asymmetrical interleaver based on Michelson Gires-Tournois interferometer(MGTI) is presented.Parameters of the structure can be obtained conveniently by the method.The expression of light-wave electricity vector in transmission and reflection is simplified firstly through z transform.Then together with the design method of ellipse filter,the length of Gires-Tournois etalon(GTE),interferometer arm length difference and GTE front surface mirror reflectance can be obtained by utilizing the pole values.The design instance of a 25 GHz asymmetrical interleaver with duty cycle 1:3 is given in the paper.A number of simulation results gotten by different GTEs are given and compared.At last,the theory of designing random duty cycle interleaver is analyzed and the design instances of four different duty cycles at three order structure are given,meantime,the simulation results and the corresponding design parameters with duty cycle of 1:4 at different orders are given and compared.