精细调谐电增益环腔光电振荡器

Precise tunable optoelectronic oscillator based on electrical gain ring resonator cavity

为了有效实现光电振荡器(OEO)输出频率精细调谐,提出了一种基于电增益环腔(EGRR)的OEO。利用放大器、滤波器和移相器构成可调谐EGRR,通过改变EGRR内信号的相位等效实现环腔长度的改变,得到不同频率的射频(RF)信号,RF信号与OEO产生的自由振荡信号电注入锁定,输出信号的频率由锁定EGRR输出频率的OEO模式决定,相位噪声由OEO决定。在简单结构实验的条件下,有效实现了OEO输出频率精细调谐。实验结果表明,当光纤长为2km、EGRR长为0.5m时,得到了频率为11.3GHz、边模抑制比(SMSR)为48dB、可调谐范围为239MHz、调谐最小步长为100kHz和相位噪声为-99dBc/Hz@10kHz的RF信号。

A kind of electrical gain ring resonator （EGRR） optoelectronic oscillator （OEO） is demonstra- ted,whose frequency can be precisely tuned by a little change. The electrical gain ring resonator is com- posed of electrical amplifier, filter and electrical phase shifter which generates tunable output RF signal by equally controlling the length of ring resonator. The injection locked scheme injects the single loop OEO signal into the electrical gain ring resonator cavity. The frequency of electrical gain ring resonator is pulled by the injected signal,the frequency of the output signal is controlled by the OEO mode which locks electrical gain ring resonator frequency, and the phase noise is determined by the OEO loop. The setup of this experiment is simple and it realize precise tunable output signal. In the experiment, the length of fiber is 2 km and the length of electrical loop is 0.5 m. The structure achieves 11.3 GHz fun- damental oscillation with 48 dB side mode suppression ratio （SMSR） ,the tunable range is 239 MHz,the tunable step is 100 kHz,and the phase noise of the signal is --99 dBc/Hz at 10 kHz.