As the conventional fiber Mach-Zehnder (M−Z) interference structure being sensitive to temperature variation and mismatching of arm length in Differential Phase Shift Keying (DPSK) system, we proposed a modulation and demodulation system of DPSK based on novel M−Z interference structure. This novel M−Z interference structure has some advantages of higher temperature stability, better robustness and lower restriction of laser linewidth. A detailed discussion of the working principle is presented and demonstrated, the influences of the delay induced by arm mismatching and temperature variation on the Q factor of DPSK system are analyzed. Experimental results as well as simulations show that the delay length mismatching corresponding to descent point of 3dB increases from [0.925,1.124] to [0.536,1.31], which reduces the requirement for the length accuracy of the interference arm, and the demodulation effect of the novel structure is better under the same deviation. The Q factor of the system keeps fluctuation within a narrow range when the temperature variation in the range of 20°C–120°C, and the demodulation effect of the system is almost unaffected by the variation of ambient temperature.

由于差分相移键控（DPSK）系统中传统的光纤马赫-曾德尔（M-Z）干涉结构对温度变化和臂长失配敏感，因此，我们提出了一种基于新型M-Z干涉的DPSK调制解调系统。结构体。这种新颖的MZ干涉结构具有较高的温度稳定性，更好的鲁棒性和较低的激光线宽限制等优点。给出并论证了工作原理的详细讨论，分析了臂不匹配和温度变化引起的延迟对DPSK系统Q因子的影响。实验结果和仿真结果表明，与3dB下降点相对应的延迟长度失配从[0.925,1.124]增至[0.536,1.31]，减少了对干涉臂长度精度的要求，并且在相同偏差下新型结构的解调效果更好。当温度在20°C–120°C范围内变化时，系统的Q因子将波动保持在狭窄的范围内，并且系统的解调效果几乎不受环境温度变化的影响。