研究了一种基于双相位调制器（PM）结构的光电振荡器（OEO）。利用OEO提取的电时钟对外加的连续光进行相位调制，再经过光带通滤波器（OBPF）进行偏移滤波，产生了脉宽为7.6 ps的光脉冲。随后进入由相位调制器和单模光纤（SMF）组成的脉冲压缩器进行脉冲压缩，从而得到脉宽很窄的光帧时钟。实验中，成功实现了从4×25 Gbit/s信号中同时提取出25 GHz的光时钟和电时钟。光时钟的脉冲宽度为3.1 ps，占空比为7.75%，时间抖动为135 fs（100 Hz~10 MHz）。电时钟载噪比为61.7 dB，时间抖动为118 fs（100 Hz~10 MHz）。

An optoelectronic oscillator (OEO) on the basis of two phase modulators is proposed. The incident continuous wave (CW) light is modulated firstly by a phase modulator (PM). The PM is driven by the electrical prescaled clock extracted from this improved OEO. The spectrum of the modulated CW light is then sliced by an optical band-pass filter (OBPF) on the blue side or red side to the original center wavelength. The generated 7.6 ps optical pulses are subsequently launched into a pulse compressor, which consists of a PM and a single-mode-fiber (SMF). Thereby, optical prescaled clock with a narrow width is then obtained. 25 GHz optical clock and electrical clock are experimentally extracted from 4×25 Gbit/s signal. The width of optical clock pulse is 3.1 ps, which corresponds to a duty cycle of 7.75%. The resulted timing-jitter (100 Hz to 10 MHz) is 135 fs. The carrier-to-noise ratio of electrical clock is 61.7 dB and its timing jitter (100 Hz to 10 MHz) is 118 fs.