报道了一种光纤型宽调谐中红外差频产生(DFG)激光光源,该系统分别以掺镱光纤激光器(YDFL)和 掺铒光纤激光器(EDFL)作为泵浦和信号源。为拓宽基频光调谐范围,采用了4个不同工作波段的YDFL, 并通过电控光开关实现段间的快速切换,总调谐范围为 nm;采用电控偏振控制器 (ECPC)分别对基频光偏振态进行精确快速控制,以提高系统转化效率;利用PID算法和负反馈技术分别稳定 泵浦LD温度和驱动电流,并将其工作状态通过LCD实时显示。测试结果表明,该中红外激光系统可在3.04~3.72 μm内连续调谐。

A widely tunable mid-infrared difference frequency generation (DFG) laser source is reported which uses ytterbium doped fiber lasers (YDFL) and an erbium doped fiber laser (EDFL) as the fundamental lights respectively. By using an electronically controlled optical switch to choose one of different tuning bands respectively supplied by four tunable YDFLs and to quickly switch among them, the whole tuning range of the pump light is broadened to be between 1040nm and 1110nm. Two electronically controlled polarization controllers (ECPC) respectively operating in 1060nm and 1550nm waveband are also used to precisely adjust polarizations of the pump and signal lights, so as to improve the conversion efficiency of the DFG system. The PID algorithm and feedback technique are used to control the temperature and driving current of the pump LDs, the controlled conditions are displayed with an LCD. The measurement results show that the mid-infrared laser system may be continuously tuned within the range of 3.04~3.72 μm.