为改善全光纤三端口Interleaver的输出特性, 提出了一种基于双“8”字型光纤谐振环的对称结构三端口全光纤Interleaver。该谐振环由一个一字型3×3单模光纤耦合器和两个2×2单模光纤耦合器组成双“8”字型作为输入耦合器, 而一个品字型3×3单模光纤耦合器作为输出耦合器。理论和实验分析了该波长交错器的输出特性, 结果表明: 与两级级联马赫-曾德尔干涉仪型(TCMZI)全光纤三端口Interleaver相比, 其输出波形通带更加平坦, 通带和阻带加宽, 信道间功率旁瓣降低了约24 dB。通过实验用光纤熔融拉锥法制作了该器件, 结果显示实验结果与理论分析吻合得很好, 实验样品的信道间旁瓣值小于-30 dB, 信道隔离度大于30 dB。

In order to improve the transmission performance of all-fiber three-channel interleavers, an all-fiber three-channel interleaver was developed by using a new configuration of dual-8-shaped ring resonator.The ring was composed of a planar 3×3 single mode fiber coupler and two 2×2 fiber couplers and was used as an input device. Furthermore, a regular triangle 3×3 fiber coupler was used as output device. The propagation properties of the three-channel interleaver were studied experimentally and theoretically. Obtained result indicates that the sidelobe level of channel of the proposed device is reduced by more than 24 dB and the crosstalk characteristics, channel isolation, the bandwidth of passband/stopband, the rolloff in transition band and the coupling-coefficient tolerance have been improved greatly in comparison with that of the convention all-fiber three-channel interleaver based on a two-stage cascaded Mach-Zehnder interferometer(TCMZI). This kind of interleaver was fabricated with a fused biconical taper technics in an experiment. The experimental results are in good agreement with the analytical ones and it shows that the measured sidelobe level is about -30 dB and the channel isolation is higher than 30 dB.