Liu Sicong, Zhang Yani, Li Lu, Wang Yonggang, Lv Ruidong, Wang Xi, Chen Zhendong, Wei Lianglei
Appl Opt. 2018 Feb 20;57(6):1292-1295. doi: 10.1364/AO.57.001292.
A stable Q-switched Er-doped fiber (EDF) laser is successfully obtained by using a black phosphorus (BP)/polymethyl methacrylate (PMMA) film as the saturable absorber (SA). To avoid the oxidization of nanomaterials, the BP nanoparticles are fabricated via a liquid-phase exfoliation method and then embedded into a PMMA film that possesses excellent optical transparency in the selected spectrum range. The modulation depth (MD) of the BP/PMMA film SA is 14.3% and the saturable intensity (I) is 6.9 MW/cm. By inserting the BP/PMMA film into the EDF laser cavity, we achieve the stable passive Q-switching operation over the wavelength range from 1561.21 nm to 1564.16 nm. The repetition rate increases from 10.348 kHz to 30.098 kHz, and the pulse duration decreases from 25.01 μs to 2.98 μs by altering the pump power from 9 mW to 90 mW. The maximum single pulse energy is 283.91 nJ. To the best of our knowledge, 283.91 nJ is the largest single pulse energy among the Q-switched fiber lasers with BP as the Q-switcher at the 1.5 μm wavelength region. The experimental results evidently show that the BP/PMMA film SA can work as a promising Q-switcher for large pulse energy fiber lasers.
通过使用黑磷（BP）/聚甲基丙烯酸甲酯（PMMA）薄膜作为饱和吸收体（SA），成功获得了一种稳定的调Q掺铒光纤（EDF）激光器。为避免纳米材料氧化，采用液相剥离法制备BP纳米颗粒，然后将其嵌入在选定光谱范围内具有优异光学透明度的PMMA薄膜中。BP/PMMA薄膜SA的调制深度（MD）为14.3%，饱和强度（I）为6.9 MW/cm²。通过将BP/PMMA薄膜插入EDF激光腔中，我们在1561.21 nm至1564.16 nm波长范围内实现了稳定的被动调Q运转。通过将泵浦功率从9 mW改变到90 mW，重复频率从10.348 kHz增加到30.098 kHz，脉冲宽度从25.01 μs减小到2.98 μs。最大单脉冲能量为283.91 nJ。据我们所知，283.91 nJ是在1.5 μm波长区域以BP作为调Q开关的调Q光纤激光器中最大的单脉冲能量。实验结果清楚地表明，BP/PMMA薄膜SA可作为一种有前景的用于大脉冲能量光纤激光器的调Q开关。
