Ultrafast Molecular Spectroscopy Using a Hollow-Core Photonic Crystal Fiber Light Source.
Ultrafast Molecular Spectroscopy Using a Hollow-Core Photonic Crystal Fiber Light Source.
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DOI：
10.1021/acs.jpclett.8b03777
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发表时间：
2018-12
期刊：
影响因子：
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通讯作者：
N. Kotsina;F. Belli;Shou-fei Gao;Ying‐ying Wang;Pu Wang;J. Travers;D. Townsend
中科院分区：
文献类型：
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作者：
N. Kotsina;F. Belli;Shou-fei Gao;Ying‐ying Wang;Pu Wang;J. Travers;D. Townsend
首次将稀有气体填充空芯光子晶体光纤(HC-PCF)作为可调谐紫外光光源应用于飞秒泵浦-探测光谱分析。这里的一个关键要求是在更长的数据采集周期内具有良好的输出稳定性，我们证明这是很容易实现的。时间分辨光电子成像技术揭示了在242-258 nm区域激发后，在三个不同的时间尺度上运行的非绝热动力学过程。其中包括S2(ππ*)和S1(ππ*)电子态之间的超快(<；100fs)内部转换以及随后在S1(ππ*)内的分子内振动能量重新分配。紧凑型、高性价比和高效率的台式HC-PCF光源具有巨大的潜力，可以为紫外线和真空紫外光谱区域的超快光谱开辟许多令人兴奋的新途径。我们预计，我们对这一方法的初步验证将在这一领域产生重要的推动作用。
We demonstrate, for the first time, the application of rare-gas-filled hollow-core photonic crystal fibers (HC-PCFs) as tunable ultraviolet light sources in femtosecond pump-probe spectroscopy. A critical requirement here is excellent output stability over extended periods of data acquisition, and we show this can be readily achieved. The time-resolved photoelectron imaging technique reveals nonadiabatic dynamical processes operating on three distinct time scales in the styrene molecule following excitation over the 242-258 nm region. These include ultrafast (<100 fs) internal conversion between the S2(ππ*) and S1(ππ*) electronic states and subsequent intramolecular vibrational energy redistribution within S1(ππ*). Compact, cost-effective, and highly efficient benchtop HC-PCF sources have huge potential to open up many exciting new avenues for ultrafast spectroscopy in the ultraviolet and vacuum ultraviolet spectral regions. We anticipate that our initial validation of this approach will generate important impetus in this area.