Long Xin, Zou Weiwen, Chen Jianping
Opt Express. 2016 Mar 7;24(5):5162-5171. doi: 10.1364/OE.24.005162.
Pulse compression processing based on stimulated Brillouin scattering (SBS) in an optical fiber is theoretically and experimentally demonstrated. Broadband microwave signal is electro-optically modulated onto the pump lightwave that is launched into one end of the fiber. Acoustic wave in the fiber inherits the amplitude and phase information of the pump lightwave and thus the coupling between the acoustic wave and pump lightwave leads to the auto-correlated process of the pump lightwave as well as the modulated microwave signal. Derivation of the SBS coupling equations shows that the short-pulse probe lightwave amplified by the pump lightwave possesses the nature of auto-correlation formula. All-optical pulse compression of the broadband microwave signal is implemented after a subtraction between the detected probe pulse with and without SBS. A proof-of-concept experiment is carried out. The pulse compression of a linear frequency-modulated microwave signal with 1 GHz sweep range at the carrier frequency of 4.3 GHz is successfully realized, which well matches the theoretical analysis.
基于光纤中受激布里渊散射（SBS）的脉冲压缩处理在理论和实验上均得到了验证。宽带微波信号通过电光调制加载到注入光纤一端的泵浦光波上。光纤中的声波继承了泵浦光波的幅度和相位信息，因此声波与泵浦光波之间的耦合导致了泵浦光波以及调制微波信号的自相关过程。SBS耦合方程的推导表明，由泵浦光波放大的短脉冲探测光波具有自相关公式的性质。在对有无SBS情况下检测到的探测脉冲进行减法运算后，实现了宽带微波信号的全光脉冲压缩。开展了概念验证实验。成功实现了载波频率为4.3 GHz、扫描范围为1 GHz的线性调频微波信号的脉冲压缩，与理论分析结果吻合良好。
