A mathematical research on flattop all-fiber MZI interleaver based on double-deviations models and uniform design method

In this paper, a novel Double-Deviations mathematical model and Uniform Design Method for flattop all-fiber MZI interleaver is proposed. It provides an innovative, versatile and practical solution for the design of cascaded MZI filters. Obtain the parameters of the all-fiber comb filters by constructing the uniform design table, then the scheme is numerically simulated and verified in three different structures. When evaluating the performance of flattop all-fiber interleave, a new goodness-of-fit criterion named "double difference function of the optical comb transform output spectrum and the target square wave"was established. It can adequately consider the information provided by evaluation index of the output waveform. The geometrical significance of Double-Deviations and the convergence proof of function sequence based on it is described and analyzed. The preliminary numerical simulation results show that the flattop all-fiber MZI filters designed under Uniform Design Method have optimum performance. When compared with the output waveform obtained by the traditional algorithm, the scheme proposed has less calculation time, high approximation accuracy, flatter pass-band and stop-band of the filter, whose advantage is highlighted obviously for solving high dimension parameter optimization problem in the optical fiber field.