提出并分析验证了一种由光场往返调制实现的光域双环路光电振荡器(OEO)。系统中光信号往返两次通过马赫曾德尔调制器(MZM)后再进行反馈调制，使得环路中的光纤延时利用率加倍，并构成两个不同环长的光学环路。理论上对该结构的起振条件和双环选模原理进行了分析，经过与传统单环光电振荡器实验对比，此结构能有效提高边模抑制比，所测得的边模抑制比为48.33 dB，在频偏10 kHz时的单边带相位噪声为-97.35 dBc/Hz。该结构无需增加有源器件，降低了系统中光纤的使用量，简化了实验的控制参数。信号在两个环路中循环时相向传输，进而消除了随机干涉和拍噪声引入。

A dual-loop optoelectronic oscillator (OEO) with reciprocating optical path is presented. The utilization ratio of delay for a fiber can be doubled due to feedback modulation after the optical signal passed through the Mach-Zehnder modulator (MZM) twice. And two optical loops with different lengths can be formed in the same way. This mechanism is based on the theoretical analysis of the oscillate condition and mode selection principle of the dual-loop configuration about this dual-loop configuration is analyzed. Furthermore, compared with the conventional optoelectronic oscillator, the experimental results show that such dual-loop configuration can effectively improve the side-mode suppression ratio and the side-mode suppression ratio is 48.33 dB, the single side band phase noise is -97.35 dBc/Hz at 10 kHz of frequency offset. In addition, the consumption of fibers can be reduced and the control parameters are sampled since no extra active devices in this dual-loop OEO are needed. The random interference and beat noise can be eliminated when the signal in the two loops transmits in opposite direction.