基于DFB腔注入锁定效应的可调谐光电振荡器（英文）

Tunable Optoelectronic Oscillator Based on Injection-locking Effect in Distributed Feed-back Laser Diode

提出一种基于分布反馈光注入锁定效应的可调谐光电振荡器,其环路主要由马赫曾德尔调制器、光电探测器、环形器、分布反馈激光器和射频放大器顺接而成.分布反馈激光器是系统关键器件,通过分布反馈激光器光注入锁定效应,分布反馈腔在光域实现了微波光子滤波器功能,无需传统光电振荡器必须的射频带通滤波器.同时,由于分布反馈激光器注入锁定提高了环路Q值,因此系统可采用短环路结构,从而降低了光纤因温度敏感对微波信号稳定性的影响并减小了整个系统的尺寸.另外,通过调节注入光波长和功率可改变该微波光子滤波器的中心频率,从而可实现系统的可调谐性.理论分析了该光电振荡器的原理和微波光子滤波器的调谐性,在此基础上开展了实验验证.结果表明该光电振荡器能够产生18.7~21.6GHz的可调微波信号,在1kHz频偏处的相位噪声为-90dBc/Hz.

A tunable optoelectronic oscillator was proposed by utilizing optical injection-locking effect in a distributed feed-back laser diode. The optoelectronic oscillator loop mainly consists of an intensity modulator, a photodetector, an optical circulator, a distributed feed-back laser diode and a broad band radio frequency amplifier. In the proposed configuration, the distributed feed-back laser diode is key device. By utilizing injection locking of distributed feed-back laser diode rather than the commonly used radio-frequency band-pass filter, a high Q microwave filter is formed in optical domain, and short optoelectronic oscillator loop could be used in the proposed scheme. Thereby the effect of temperature sensitive of fiber on microwave signal stability can be declined and the system size can be reduced. Meanwhile, the central frequency of the microwave filter could be simply tuned and the tunability could be realized by tuning the wavelength and the injection power of the injection light. Theoretical analysis of the optoelectronic oscillator as well as the tunability of microwave filter was provided. Thus, experiment was done to verify the theoretical analysis. The results show that the proposed optoelectronic oscillator can produce the microwave signal with tunable range from 18.7 GHz to 21.6 GHz, and the measured phase noise at 1 kHz offset is -90 dBc/Hz.