Design of strain-introduced MZI interleaver on LiNbO3 substrate

A strain-introduced Mach-Zehnder interferometer (MZI) interleaver on lithium niobate (LiNbO3 ) is proposed. The structure of the strain-introduced waveguide is designed in detail, and is produced by depositing a SiO2 film on the annealed proton-exchanged LiNbO3 waveguide. Considering the sensitivities of the edge strain to the deposition temperature and the thickness of the SiO2 film, an optimum design of 50 GHz interleaver on this structure is given through analyzing the effective index changes for E x pq mode by finite difference method (FDM). The length of the bending waveguide in this interleaver is just two thirds of that in the conventional interleaver due to the high refractive index difference.     

基于平板光波导任意带宽比的新型非对称交错滤波器

为了提高目前光纤通信系统的10 Gbit/s和40 Gbit/s混合系统的传输效率,提出了一种新型的器件结构以实现基于平面光波导的不等带宽交错滤波器。该结构结合光学微环与马赫曾德尔干涉仪结构,通过控制相关关键参数,实现了任意带宽比的光学交错滤波器,给出了带宽比为12的非对称交错滤波器设计实例。仿真结果表明,设计的交错滤波器在信道间隔为100 GHz的系统中给传输速率为10 Gbit/s和40 Gbit/s的两个信道分别分配了32.85 GHz和67.15 GHz的带宽,从而解决了传输速率为40 Gbit/s的信道带宽不足的问题。在此基础上通过分析器件中各双模干涉仪的光功率分配比对输出谱带宽比的影响,给出了在相同信道间隔条件下不同带宽比的非对称交错滤波器的设计实例。     

基于改进神经网络的三字词声调识别方法

汉语连续语音三字词声调由于受声道响应、音连、变调规律等的影响,情况较复杂,声调模式间交集大,模糊性强。提出了一种基于动态时间规整和改进神经网络的声调识别算法。实验表明,该算法可得到较好的识别效果,对探讨具有汉语特色的新的语音识别方法有重要意义。