Microwave generation with photonic frequency octupling using a DPMZM in a Sagnac loop
Microwave generation with photonic frequency octupling using a DPMZM in a Sagnac loop
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DOI：
10.1080/09500340.2015.1034793
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发表时间：
2015-04
影响因子：
1.3
通讯作者：
Yongsheng Gao;A. Wen;Ningning Li;Xiaohui Wu;Huixing Zhang
中科院分区：
文献类型：
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作者：
Yongsheng Gao;A. Wen;Ningning Li;Xiaohui Wu;Huixing Zhang
提出了一种利用八倍频技术产生光子微波信号的方案，并进行了实验验证。该方案是基于双向使用的双并行马赫-曾德尔调制器（DPMZM）的Sagnac环。DPMZM中的两个子调制器由两个相位差为π/2的低频信号驱动，调制器的直流偏置均设置在最大传输点。由于调制器的速度失配，仅沿着顺时针方向的光波被驱动信号有效地调制以生成具有载波和± 4阶边带的光信号，而沿着逆时针方向的光波的调制远不如其有效并且可以被忽略。通过适当调节Sagnac环输出光波的偏振态，可以在起偏器处显著抑制光载波，从而产生只有± 4阶边带的光信号。在实验中，一个纯的24 GHz的微波信号，没有额外的相位噪声从光学系统中产生的使用3 GHz的本地振荡器信号。由于没有使用电或光滤波器，光子频率八倍器具有良好的频率可调谐性。
A photonic microwave signal generation scheme with frequency octupling is proposed and experimentally demonstrated. The scheme is based on bi-directional use of a dual-parallel Mach–Zehnder modulator (DPMZM) in a Sagnac loop. The two sub-modulators in the DPMZM are driven by two low-frequency signals with a π/2 phase difference, and the dc biases of the modulator are all set at the maximum transmission points. Due to the velocity mismatch of the modulator, only the light wave along the clockwise direction is effectively modulated by the drive signals to generate an optical signal with a carrier and ±4th order sidebands, while the modulation of the light wave along the counterclockwise direction is far less effective and can be ignored. By properly adjusting the polarization of the light wave output from the Sagnac loop, the optical carrier can be significantly suppressed at a polarizer, and then an optical signal with only ±4th order sidebands is generated. In the experiment, a pure 24-GHz microwave signal without additional phase noise from the optical system is generated using a 3-GHz local oscillator signal. As no electrical or optical filter is used, the photonic frequency octupler is of good frequency tunability.