Self-phase modulation enabled, wavelength-tunable ultrafast fiber laser sources: an energy scalable approach
Self-phase modulation enabled, wavelength-tunable ultrafast fiber laser sources: an energy scalable approach
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DOI：
10.1364/oe.24.015328
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发表时间：
2016-07-11
期刊：
影响因子：
3.8
通讯作者：
Chang, Guoqing
中科院分区：
文献类型：
--
作者：
Liu, Wei;Li, Chen;Chang, Guoqing
我们提出并论证了一种用于多光子显微镜的波长可调的超快光纤激光光源的实现方法。我们利用光纤非线性展宽Yb光纤激光系统产生的窄带光谱，然后使用光学带通滤光器从展宽的光谱中选择最左边或最右边的光谱波瓣。详细的数值模拟表明，自相位调制对光谱展宽起主导作用，自陡化使展宽光谱蓝移，受激拉曼散射最小。我们还发现，光纤色散引起的光波破裂减缓了最左/最右光谱瓣的移动，从而限制了滤波光谱的波长调谐范围。数值和实验表明，缩短用于光谱展宽的光纤，同时增加输入脉冲能量，可以克服这种色散引起的限制；因此，滤波后的谱瓣具有更高的功率，构成了一种强大而实用的能量标度飞秒源的方法。我们使用了两种商用光子晶体光纤来验证模拟结果。更具体地说，使用20 mm光纤NL-1050-ZERO-2使我们能够实现基于Yb光纤激光器的超快光源，以>；1 nJ的脉冲能量提供从825 nm到1210 nm可调的飞秒(70-120飞秒)脉冲。(C)2016年度美国光学学会
We propose and demonstrate a new approach to implement a wavelength-tunable ultrafast fiber laser source suitable for multiphoton microscopy. We employ fiber-optic nonlinearities to broaden a narrowband optical spectrum generated by an Yb-fiber laser system and then use optical bandpass filters to select the leftmost or rightmost spectral lobes from the broadened spectrum. Detailed numerical modeling shows that self-phase modulation dominates the spectral broadening, self-steepening tends to blue shift the broadened spectrum, and stimulated Raman scattering is minimal. We also find that optical wave breaking caused by fiber dispersion slows down the shift of the leftmost/rightmost spectral lobes and therefore limits the wavelength tuning range of the filtered spectra. We show both numerically and experimentally that shortening the fiber used for spectral broadening while increasing the input pulse energy can overcome this dispersion-induced limitation; as a result, the filtered spectral lobes have higher power, constituting a powerful and practical approach for energy scaling the resulting femtosecond sources. We use two commercially available photonic crystal fibers to verify the simulation results. More specific, use of 20-mm fiber NL-1050-ZERO-2 enables us to implement an Yb-fiber laser based ultrafast source, delivering femtosecond (70-120 fs) pulses tunable from 825 nm to 1210 nm with > 1 nJ pulse energy. (C) 2016 Optical Society of America