Pushkin A V, Migal E A, Tokita S, Korostelin Yu V, Potemkin F V
Opt Lett. 2020 Feb 1;45(3):738-741. doi: 10.1364/OL.384300.
We report, for the first time, to the best of our knowledge, a femtosecond mode-locked Fe:ZnSe laser. Passive mode locking is implemented using graphene as a saturable absorber. The laser operates at 4.4 µm with a repetition frequency of 100 MHz and 415 mW output power pumped by a fiber 7 W Er:ZBLAN laser. The pulse duration of about 732 fs is retrieved from the first-order autocorrelation function. Additionally, we observe pulsed nanosecond oscillation under continuous-wave pumping and strong amplitude modulation caused by Kerr self-focusing. This Letter fills the gap in operating regimes of Fe:ZnSe lasers and paves the way for the development of powerful ultrafast high-repetition-rate mid-IR sources for the most advanced fields of science.
据我们所知，我们首次报道了一种飞秒锁模铁掺杂硒化锌（Fe:ZnSe）激光器。利用石墨烯作为可饱和吸收体实现被动锁模。该激光器在4.4 µm波长下工作，重复频率为100 MHz，由一台7 W的光纤铒掺杂氟锆酸盐（Er:ZBLAN）激光器泵浦，输出功率为415 mW。从一阶自相关函数中测得脉冲持续时间约为732 fs。此外，我们观察到在连续波泵浦下出现了纳秒级脉冲振荡以及由克尔自聚焦引起的强幅度调制。这封信填补了Fe:ZnSe激光器工作模式方面的空白，并为在最先进的科学领域开发强大的超快高重复率中红外光源铺平了道路。
