基于被动同步的宽调谐中红外差频技术研究

Study on Widely Tunable Mid-Infrared Difference-Frequency Generation Based on Passive Synchronization

实验搭建了基于同步脉冲泵浦的非线性差频中红外光源,利用主-从注入式全光调制技术实现了保偏掺饵和掺镱锁模光纤激光器的被动同步输出,结合高非线性光纤光谱展宽和宽带可调谐滤波器,获得了2940~3260 nm宽波段可调谐的中红外皮秒激光,平均功率为580~926 mW,最大泵浦光转换效率为41%。实验发现,小功率的同步诱导脉冲注入可以大幅降低中红外参量产生的泵浦阈值,从而放宽了高效率中红外产生对高功率泵浦光场的要求。

We have experimentally implemented a difference-frequency-generated mid-infrared(MIR)source based on synchronously pulsed pumping.The passive synchronization between polarization-maintaining Er-and Yb-doped mode-locked fiber lasers was realized by using all-optical modulation technique via master-slave injection.By combining spectral broadening of highly nonlinear fiber and wide-band tunable filter,we could obtain broadly tunable MIR picosecond laser from 2940 nm to 3260 nm.The average power was 580 mW to 926 mW,and the maximum pump conversion efficiency was 41%.In the experiment,the injection of low-power synchronous induced pulses could substantially reduce the pumping threshold for the MIR parametric generation,which would relax the requirement of strong pump field to realize efficient MIR generation.