Opt Lett. 2019 Jan 1;44(1):94-97. doi: 10.1364/OL.44.000094.
We report a photonic scheme to generate background-free frequency-doubled binary phase-coded microwave pulses. The key component is a dual-polarization dual-parallel Mach-Zehnder modulator that is used to realize phase modulation and carrier-suppressed double second-order sideband modulation at two orthogonal polarization states, respectively. The π phase jump of the frequency-doubled phase-coded microwave pulse is dependent on the polarity of the coding signal rather than its amplitude. Besides, the generated microwave pulses are free from the baseband-modulated signals, because the optical power launched to a photodetector (PD) keeps constant all the time. Since no electrical or optical filters are involved, the photonic generator can ensure a broad operation bandwidth and wide tunability. Our scheme is theoretically analyzed and experimentally verified. The 4 Gb/s at 16 GHz and 7 Gb/s at 28 GHz background-free frequency-doubled phase-coded microwave pulses have been successfully generated.
我们提出了一种产生无背景的倍频二进制相位编码微波脉冲的光子方案。该方案的关键组件是一个双偏振双平行马赫-曾德尔调制器，它分别用于实现两个正交偏振态的相位调制和载波抑制双二阶边带调制。倍频相位编码微波脉冲的π 相移取决于编码信号的极性，而不是其幅度。此外，由于发射到光电探测器 (PD) 的光功率始终保持恒定，因此所产生的微波脉冲不受基带调制信号的影响。由于不涉及电或光滤波器，光子发生器可以确保宽的工作带宽和宽的可调谐性。我们的方案进行了理论分析和实验验证。已经成功生成了 4 Gb/s@16 GHz 和 7 Gb/s@28 GHz 的无背景倍频二进制相位编码微波脉冲。
