Zeng Zhen, Zhang Lingjie, Wu Yilin, Zhang Zhiyao, Zhang Shangjian, Zhang Yali, Sun Bao, Liu Yong
Opt Express. 2021 Sep 13;29(19):30834-30843. doi: 10.1364/OE.439471.
A novel approach to generating multi-format microwave signals directly from an optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. Through applying different low-frequency electrical waveforms to the bias port of the electro-optic Mach-Zehnder modulator, the net gain in the OEO cavity is dynamically controlled to make the OEO work at different status. Hence, different microwave signals can be generated in the oscillation process. In the proof-of-concept experiment, a single-tone microwave signal at 4.005 GHz is generated by using a direct-current driving voltage. Microwave pulse trains centered at 4 GHz and with repetition rates of 390 kHz and 3.9 MHz are generated under fundamental and 10th-order harmonic mode locking, respectively, by using sinusoidal driving voltages. Besides, rectangular microwave waveforms centered at 4 GHz and with duty cycles of 25%, 50%, and 75% are generated under gain switching status by using rectangular driving voltages. The proposed method is also able to generate other types of microwave signals in a broad frequency range, which can find applications in a multi-functional microwave photonic system.
提出并通过实验证明了一种直接从光电振荡器（OEO）生成多格式微波信号的新方法。通过将不同的低频电波形应用于电光马赫-曾德尔调制器的偏置端口，动态控制OEO腔中的净增益，使OEO工作在不同状态。因此，在振荡过程中可以生成不同的微波信号。在概念验证实验中，使用直流驱动电压生成了4.005 GHz的单音微波信号。通过使用正弦驱动电压，分别在基模和十阶谐波锁模下生成了中心频率为4 GHz、重复率为390 kHz和3.9 MHz的微波脉冲序列。此外，通过使用矩形驱动电压，在增益开关状态下生成了中心频率为4 GHz、占空比为25%、50%和75%的矩形微波波形。所提出的方法还能够在很宽的频率范围内生成其他类型的微波信号，可在多功能微波光子系统中找到应用。
