提出了一种全新的基于相位-强度混合调制和色散补偿的光差分相移键控(DPSK)信号的非归零(NRZ)到归零(RZ)格式转换器，理论分析了转换器参数对转换的影响，数值研究了恶化条件下的10 Gb/s的NRZ-DPSK到RZ-DPSK的格式转换。实验展示了10 Gb/s 的DPSK信号格式转换及解调后的误码性能。计算结果表明，通过设计转换器参数可获得低占空比RZ-DPSK信号，且转换后信号质量较高。实验结果表明格式转换功率代价较低，转换后RZ-DPSK信号时间抖动较原NRZ-DPSK信号减小。该格式转换器还适合光四相差分相移键控(DQPSK)的非归零到归零格式转换及多波长操作。

A novel non-return-to-zero (NRZ) to return-to-zero (RZ) format converter for differential phase shift keying (DPSK) signal is proposed based on phase-intensity hybrid modulation and dispersion compensation. Influence on the format conversion of the converter parameters is theoretically analyzed and format conversion of 10-Gb/s degraded DPSK signal is investigated through numerical simulation. Experimental 10-Gb/s NRZ-DPSK signal to RZ-DPSK signal conversion and the bit error rate (BER) performance of the demodulated signals have also been demonstrated. Calculation results show that low duty cycle RZ-DPSK signal with high quality can be obtained through designing the converter. Experimental results show that the power penalty of the conversion is low and the timing-jitter of the RZ-DPSK signal is lower than that of the NRZ-DPSK signal. The format converter can also be applicable to multi-wavelength and differential quadrature phase shift keying (DQPSK) operation.