ONERA-The French Aerospace Laboratory, Palaiseau, France.
Opt Lett. 2011 Mar 1;36(5):751-3. doi: 10.1364/OL.36.000751.
We report on a nonlinear mirror (NLM) scheme that enables, for the first time to the best of our best knowledge, tunable mode locking of a Cr2+:ZnSe laser in the picosecond regime. The NLM-used as the output coupler of the laser cavity-consists of a periodically poled lithium niobate (PPLN) crystal with a fan-out grating coupled with a dichroic mirror and a wedged dispersive YAG plate. The Cr2+:ZnSe laser, pumped by a CW thulium-doped fiber laser, delivers 85 ps pulses at a repetition rate of 220 MHz with a 300 mW average power. Thanks to the use of a fan-out PPLN crystal, we benefit from the wide tunability of the Cr2+:ZnSe laser and achieve mode locking over the whole 2.44-2.55 μm range while maintaining a narrow-linewidth emission suitable for time-resolved nonlinear spectroscopy applications.
我们报告了一种非线性镜 (NLM) 方案，该方案首次实现了我们所知的最佳可调谐模式锁定 Cr2+:ZnSe 皮秒激光器。NLM-用作激光腔的输出耦合器-由具有扇形出射光栅的周期性极化铌酸锂 (PPLN) 晶体与二色镜和楔形色散 YAG 板组成。Cr2+:ZnSe 激光器由连续波掺铥光纤激光器泵浦，以 220MHz 的重复率输出 85ps 脉冲，平均功率为 300mW。由于使用了扇形出射 PPLN 晶体，我们受益于 Cr2+:ZnSe 激光器的宽调谐性，并在保持适合时间分辨非线性光谱应用的窄线宽发射的同时，实现了整个 2.44-2.55μm 范围内的锁模。
