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Updated: May 14, 2026

Multimodal Nonlinear Hyperspectral Chemical Imaging Using Line-Scanning Vibrational Sum-Frequency Generation Microscopy
Published on: December 1, 2023
[Vibrational to rotational energy transfer between CsH (Chi1 Sigma+, nu > or = 15) and CO2]
Kang Dai1, Shu-Ying Wang, Jing Liu
1School of Physics, Xinjiang University, Urumqi 830046, China.
Abstract:
The quenching of highly vibrational excited CsH through collisions with a 500 K bath of CO2 was investigated using the laser spectroscopy technique. CsH was formed by the Cs(7P)+H2 reaction. The pulse laser prepared CsH in the highly vibrational levels. Laser induced fluorescence was used to detect collisionally relaxed CsH. The relaxation rate coefficient of CsH (nu" = 21) with CO2 is 10 times larger than that of CsH(nu" = 15). Relaxation of CsH(nu") with H2 was also investigated. The mass effect on the collisional relaxation rate coefficients is strong. The observed collisional relaxation rate coefficients of H2 are bigger than those of CO2. Energy gain into CO2 resulting from collisions with excited CsH was probed using laser overtone spectroscopy technique. Distributions of nascent CO2 rotational population in the ground (00(0)0) state were determined. For CsH excited at nu" = 15, the scattered CO2 molecules have a rotational temperature of T(rot) = (605 +/- 50) K. For excitation at nu" = 21, the CO2 rotational temperature is T(rot) = (780 +/- 70) K. Based on the rotational temperatures, the average change in the CO2 rotational energy
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