中心博士生张斯滕的工作——Maintenance of broadband detection in photonic time-stretched coherent radar employing phase diversity的相关研究成果近期发表在Optics Express期刊上，该工作得到了国家自然科学基金的部分资助 (批准号61822508、61571292、61535006)，解决了光子时间拉伸相干雷达接收机在宽带方面所遇到的功率随频率周期性衰减的特性。此种新方案通过双输出调制器产生的具有互补频率特性的两路输出，还原理想的输出信号，消除色散所引入的功率变化问题，从而使光子时间拉伸相干雷达系统以任意拉伸倍数工作在任意频段，拓展了系统的实用性。
摘要：Frequency response fluctuation in a radar system distorts the envelope of the output signal after matched filtering, thereby impairing its broadband detection performance. Simulations are made under various types and degrees of fluctuation. The results prove that the peak power and range resolution of broadband detection suffer different levels of deterioration. Moreover, simulation results also show that two outputs with orthogonal phase diversity have complementary variation trends and their combination can effectively enhance the broadband detection performance. Based on theoretical analysis, we employ the combination of two orthogonal phase diversity to achieve broadband detection in the photonic time-stretched coherent radar. Compared with using an ordinary modulator, a dual-output-Mach-Zehnder-modulator-based system makes the dispersion-penalty-induced frequency response fluctuation decrease by 9.7 dB. For single target detection, the peak power is increased by 6.7 dB and the range resolution is improved from 8.4 cm to 4.8 cm. For two-target detection, a 6-cm spatial interval is distinguished reliably.