Yu Xiaoyue, Zhang Fangzheng, Li Xinyi, Wang Xing, Wu Gengze, Yu Yuan, Pan Shilong
Opt Lett. 2024 Aug 1;49(15):4266-4269. doi: 10.1364/OL.529972.
A stepped-frequency (SF) radar waveform generation method based on Fourier domain mode-locking (FDML) period-one laser dynamics is proposed and demonstrated. By fast controlling the optical injection strength of a semiconductor laser through electro-optical modulation, a broadband SF signal is generated. By further introducing an optoelectronic feedback loop with its round trip time delay matched with the temporal period of the SF signal, FDML is enabled through which the frequency stability, accuracy, and in-band signal-to-noise ratio are greatly improved. In the experiment, SF signals with a bandwidth of 6 GHz (12-18 GHz) and a frequency step of 150 MHz are generated. By comparing the qualities of signals generated with and without FDML, advantages of the proposed SF signal generation method are verified. Based on the proposed SF signal generation method, high-resolution inverse synthetic aperture radar (ISAR) imaging is also demonstrated, in which the 2D imaging resolution reaches 2.6 cm × 3.82 cm.
提出并演示了一种基于傅里叶域锁模（FDML）周期一激光动力学的步进频率（SF）雷达波形生成方法。通过电光调制快速控制半导体激光器的光注入强度，生成宽带SF信号。通过进一步引入一个往返时间延迟与SF信号的时间周期相匹配的光电反馈回路，实现了FDML，从而大大提高了频率稳定性、精度和带内信噪比。在实验中，生成了带宽为6 GHz（12 - 18 GHz）、频率步长为150 MHz的SF信号。通过比较有无FDML时生成信号的质量，验证了所提出的SF信号生成方法的优势。基于所提出的SF信号生成方法，还演示了高分辨率逆合成孔径雷达（ISAR）成像，其中二维成像分辨率达到2.6 cm×3.82 cm。
