Opt Lett. 2023 Jun 1;48(11):2921-2924. doi: 10.1364/OL.488711.
Coherent dual-frequency microwave signal generation using an optoelectronic oscillator (OEO) is presented and demonstrated. In the proposed OEO, a dual-band bandpass filter (DB-BPF) is utilized to select two oscillation modes. An external signal is injected into the OEO loop with its frequency equaling the frequency interval of the two oscillation modes. Owing to the modulation nonlinearity of the Mach-Zehnder modulator, the two oscillation frequencies interact with the injection frequency. When the phase and gain conditions are satisfied within the loop, injection locking between the two oscillation signals will be established, and their phases will be synchronized. The effect of gain competition in the OEO loop, which leads to single-frequency oscillation, is suppressed. An experiment is carried out, and two frequencies, of 16.083 GHz and 9.998 GHz, are generated at the same time. The phase noise values are -140.1 and -141.0 dBc/Hz @ 10 kHz, respectively. The coherence between the generated signals and sidemode suppression performance are evaluated.
本文提出并演示了基于光电子振荡器（OEO）的相干双频微波信号产生。在所提出的 OEO 中，采用双带通滤波器（DB-BPF）选择两个振荡模式。外部信号以等于两个振荡模式频率间隔的频率注入 OEO 环路。由于马赫-曾德尔调制器的调制非线性，两个振荡频率与注入频率相互作用。当环路中的相位和增益条件满足时，两个振荡信号之间将建立注入锁定，并且它们的相位将同步。抑制了 OEO 环路中导致单频振荡的增益竞争效应。进行了实验，同时产生了 16.083GHz 和 9.998GHz 两个频率。相位噪声值分别为-140.1dBc/Hz@10kHz 和-141.0dBc/Hz@10kHz。评估了所产生信号之间的相干性和边模抑制性能。
