Li Zelong, Zhang Ning, He Siyi, Lu Xu, Gong Rongyu, Wang Quanjun, Yao Jinping
School of Microelectronics, Shanghai University, Shanghai 200444, China.
State Key Laboratory of Ultra-intense Laser Science and Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China.
J Phys Chem Lett. 2025 Sep 4;16(35):9194-9201. doi: 10.1021/acs.jpclett.5c01944. Epub 2025 Aug 28.
Simultaneous detection of multiple reaction products induced by filamentation is crucial for unraveling complex atmospheric chemistry but remains challenging technically. Herein, we employ air-lasing-based coherent Raman spectroscopy to simultaneously monitor the formation and evolution of O and NO after femtosecond laser filamentation in synthetic air. Simultaneous detection of the two species reveals their distinct reaction dynamics. Experimental results show that the dynamical evolutions and accumulated concentrations of O and NO strongly depend on pump energy and reaction environment. The decreasing pump energy slows chemical reactions due to reduced reactive species concentrations. Lower energies promote O accumulation, whereas the production of NO require higher energies. Moreover, the O signal disappears in ambient air, while the NO signal in ambient air differs slightly from that in synthetic air after a sufficient reaction time. The analysis of reaction pathways qualitatively explains the experimental results. This study provides guidance for control over atmospheric chemical reactions.
同时检测由丝状化诱导产生的多种反应产物对于揭示复杂的大气化学过程至关重要，但在技术上仍然具有挑战性。在此，我们采用基于空气激光的相干拉曼光谱技术，来同时监测飞秒激光在合成空气中产生丝状化后O和NO的形成与演化。对这两种物质的同时检测揭示了它们不同的反应动力学。实验结果表明，O和NO的动力学演化及累积浓度强烈依赖于泵浦能量和反应环境。泵浦能量的降低会由于反应物种浓度的降低而减缓化学反应。较低能量促进O的累积，而NO的产生需要更高能量。此外，在环境空气中O信号消失，而在足够长的反应时间后，环境空气中NO信号与合成空气中的略有不同。对反应途径的分析定性地解释了实验结果。本研究为控制大气化学反应提供了指导。
