Microwave photonic frequency conversion, with flexible tunability and a simple structure based on a wavelength swept laser (WSL), is proposed and experimentally demonstrated. In the proposed frequency conversion system, a broadband WSL was used to generate a frequency-chirped optical carrier, which was sent to a Mach Zehnder modulator (MZM). A microwave signal, with its frequency to be converted, was applied to the MZM. The modulated signal was then sent to a dispersive device, where the waveform was compressed or expanded depending on the dispersion of the dispersive device. After photodetection, a frequency up-converted or down-converted microwave signal was generated. The tuning of the conversion frequency was achieved by adjusting the chirp rate of the optical carrier from the WSL or the dispersion of the dispersive device. The proposed approach was experimentally demonstrated. A microwave signal, with its frequency at 5 GHz, was up-converted to 5.577 GHz and down-converted to 4.936 GHz. The quality of the frequency converted microwave signal was also evaluated. The conversion performance could be further improved by introducing a WSL with a high duty cycle.

中文翻译：

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基于波长扫描激光器的微波光子频率转换

微波光子频率转换具有灵活的可调性和基于波长扫描激光器 (WSL) 的简单结构，被提出并通过实验证明。在提议的频率转换系统中，宽带 WSL 用于生成频率啁啾光载波，该载波被发送到马赫曾德调制器 (MZM)。将要转换频率的微波信号施加到 MZM。然后将调制信号发送到色散设备，在那里根据色散设备的色散压缩或扩展波形。光电探测后，产生频率上变频或下变频的微波信号。转换频率的调谐是通过调整来自 WSL 的光载波的啁啾率或色散装置的色散来实现的。实验证明了所提出的方法。频率为 5 GHz 的微波信号被上变频到 5.577 GHz，下变频到 4.936 GHz。还评估了变频微波信号的质量。通过引入具有高占空比的 WSL，可以进一步提高转换性能。