Abstract

Molecular hydrogen is a very difficult molecule to detect in a noninvasive manner. The molecule has no dipole moment. Excitation of its first electronic excited state requires light in the vacuum ultraviolet region, ~110 nm. Hydrogen has been shown to produce spontaneous Raman emission at pressures as low as 550 Torr, but the process occurs with a low quantum efficiency, and efficient collection of the emissions is difficult. Lower partial pressures of hydrogen can be detected with coherent anti-Stokes Raman spectroscopy (CARS), but the experimental apparatus can be prohibitively expensive.

High-resolution cw stimulated Raman spectroscopy in molecular hydrogen

Adelbert Owyoung
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Nanofiber enhanced stimulated Raman spectroscopy for ultra-fast, ultra-sensitive hydrogen detection with ultra-wide dynamic range

Yun Qi, Yan Zhao, Haihong Bao, Wei Jin, and Hoi Lut Ho
Optica 6(5) 570-576 (2019)

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M. D. Duncan, R. Mahon, L. L. Tankersley, and J. Reintjes
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