摘要
为了研究耦合式光电振荡器,阐述了耦合式光电振荡器的模式选择理论,给出了维持最佳锁模状态的相位匹配条件,分析了影响射频信号相位噪声的因素,进行了基于保偏机制的耦合式光电振荡器的实验研究。采用分别调节光环形腔和光电微波振荡环路中的保偏可变光纤延迟线可改变腔长的方法,获得了腔长与振荡频率的关系。同时,采用鉴频法测量了不同条件下5GHz射频信号的相位噪声,研究了影响射频信号相位噪声的因素。结果表明,耦合式光电振荡器的振荡模式取决于光环形腔的腔长,射频信号相位噪声受到光信号偏振态、相位匹配、环路长度等因素的影响。实验中获得了偏移频率10kHz处相位噪声达到-136dBc/Hz的5GHz射频信号,是目前国内已知的相位噪声最低的耦合式光电振荡器。
In order to study coupled optoelectronic oscillators （COEO） further, the mode selection theory of COEO was expounded. The phase matching condition to maintain optimum mode-locked state was given. The affecting factors of phase noise of radio frequency signal were analyzed. The experiment of COEO based on polarization-maintaining mechanism was conducted. By adjusting the polarization-maintaining variable optical fiber delay lines in the optical ring cavity and the optoelectric microwave oscillation loop to change the cavity length, the relationship between cavity length and oscillation frequency was obtained. Meanwhile, by using the frequency discrimination method, phase noise performances of 5GHz radio frequency（RF） signals under different operating conditions were measured and the effective factors were studied. The experimental results demonstrate that oscillation mode depends on the cavity length of optical ring cavity. Optical signal polarization, phase matching and loop length have influence on the phase noise of the RF signals. The coupled optoelectronic oscillator of 5GHz RF signal and phase noises of - 136dBc/Hz at 10kHz offset frequency is obtained, whose phase noise is the lowest in our country as far as we know.
出处
《激光技术》
CAS
CSCD
北大核心
2014年第5期579-585,共7页
Laser Technology
基金
国家自然科学基金资助项目(61275027)
关键词
光电子学
耦合式光电振荡器
振荡模式
相位匹配
保偏
相位噪声
optoeleetronies
coupled optoelectronic oscillator
oscillation mode
phase match
polarizationmaintaining
phase noise
