Optical generation of a megahertz-linewidth microwave signal using semiconductor lasers and a discriminator-aided phase-locked loop
Optical generation of a megahertz-linewidth microwave signal using semiconductor lasers and a discriminator-aided phase-locked loop
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DOI：
10.1109/22.618427
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发表时间：
1997-08
影响因子：
4.3
通讯作者：
F. Fan;M. Dagenais
中科院分区：
文献类型：
--
作者：
F. Fan;M. Dagenais
提出了一种具有明显增强频率捕获能力的鉴频辅助光锁相环（OPLL）。其吸合范围测量为300 MHz，可以很容易地进一步扩展。实现了两台边模抑制比大于30 dB的光栅调谐外腔半导体激光器。这两个激光器被允许在快速检测器上跳动，并被偏移锁相。发现所产生的微波信号是接近载波的参考RF信号的复制品。测量到接近载波的噪声水平为-70 dBc/Hz，并且在远离载波4 MHz处小于-100 dBc/Hz。在500 MHz带宽上，总相位方差为0.11 rad/sup 2/。直接测量锁定信号的线宽半高全宽（FWHM）为1 mHz量级。
A discriminator-aided optical phase-locked loop (OPLL) with significantly enhanced frequency acquisition capability is presented. Its pull-in range is measured to be 300 MHz and can be easily extended further. Two grating-tuned external-cavity semiconductor lasers (ECSLs) were realized with more than 30-dB side-mode suppression ratio. These two lasers were allowed to beat on a fast detector and were offset phase locked. The generated microwave signal was found to be a replica of the reference RF signal close to the carrier, The noise level was measured to be -70 dBc/Hz close to the carrier and less than -100 dBc/Hz at 4 MHz away and beyond from the carrier. The total phase variance is 0.11 rad/sup 2/ over a 500-MHz bandwidth. The linewidth full width at half maximum (FWHM) of the locked signal was directly measured to be of order 1 mHz.