Chen Zifeng, Ma Shuanglong, Yang Ying, Wang Jiachen, Yan Peiguang, Wang Jinzhang, Wang Pengfei, Jin Wei, Lue Qitao, Ruan Shuangchen, Guo Chunyu
Opt Lett. 2024 Oct 1;49(19):5451-5454. doi: 10.1364/OL.534606.
Three-micrometer mid-infrared (MIR) femtosecond pulse sources with a high repetition rate (HRR) have potential applications in a number of fields such as biological imaging, optical frequency combs, and gas detection. In this paper, by optimizing the fiber length and the cavity structure, we demonstrated a highly stable, self-starting mode-locked fluoride fiber laser (MLFFL) with a fundamental repetition rate of ∼165 MHz and a signal-to-noise ratio (SNR) of 90 dB. As far as we know, this stands as the highest fundamental repetition rate ever acquired directly from an ultrafast MLFFL in the >2.5 µm MIR region. Stable 352-fs pulses at 2795 nm with an average output power of 392 mW and a low integrated relative intensity noise (RIN) of 0.018% [10 Hz, 10 MHz] were generated. The root mean square (RMS) power fluctuation is 0.17% over 2 h, which indicates excellent oscillator stability. This high-performance laser offers a practicable scheme both for scaling the repetition frequency in MIR MLFFLs and high-precision ultrafast applications at longer wavelengths.
具有高重复率（HRR）的三微米中红外（MIR）飞秒脉冲源在生物成像、光学频率梳和气体检测等多个领域具有潜在应用。在本文中，通过优化光纤长度和腔结构，我们展示了一种高度稳定、自启动的锁模氟化物光纤激光器（MLFFL），其基频重复率约为165 MHz，信噪比（SNR）为90 dB。据我们所知，这是在>2.5 µm MIR区域直接从超快MLFFL获得的最高基频重复率。产生了中心波长为2795 nm、脉宽为352 fs、平均输出功率为392 mW且在10 Hz至10 MHz范围内具有0.018%的低积分相对强度噪声（RIN）的稳定脉冲。在2小时内，均方根（RMS）功率波动为0.17%，这表明振荡器具有出色的稳定性。这种高性能激光器为扩大MIR MLFFL的重复频率以及在更长波长下的高精度超快应用提供了一种可行的方案。
