Two-photon-excited stimulated emission from atomic hydrogen in flames

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Journal of the Optical Society of America B: Optical Physics; (USA)

DOI:https://doi.org/10.1364/JOSAB.6.001979· OSTI ID:5261449

Goldsmith, J E.M. ^[1]

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1. Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551 (US)

The first observation to the author's knowledge of optically excited stimulated emission in atomic hydrogen is described. The two-photon {ital n}=1{r arrow}{ital n}=3 transition of hydrogen atoms in low-pressure flames is excited with 205-nm radiation produced by using a beta barium borate crystal to frequency mix the fundamental and frequency-doubled radiation from a 615-nm pulsed dye laser. The resulting 656-nm {ital n}=3{r arrow}{ital n}=2 Balmer-{alpha} radiation is readily observable by eye as a coherent beam propagating in both the forward and reverse directions. A variety of characteristics of the stimulated emission are described, its behavior is compared simultaneous measurements of two-photon-excited fluorescence, and the possibility that the stimulated-emission process may affect the quantum yield of fluorescence and ionization detection methods is discussed. Potential diagnostic applications of two-photon-excited stimulated-emission detection for measuring atomic hydrogen in flames are demonstrated, using simultaneous profile measurements of stimulated emission and fluorescence signals.

• OSTI ID: 5261449
• Journal Information: Journal of the Optical Society of America B: Optical Physics; (USA), Vol. 6:11; ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COMBUSTION
DIAGNOSTIC TECHNIQUES
FLAME PHOTOMETRY
HYDROGEN
STIMULATED EMISSION
FLAMES
MULTI-PHOTON PROCESSES
CHEMICAL REACTIONS
ELEMENTS
EMISSION
ENERGY-LEVEL TRANSITIONS
NONMETALS
OXIDATION
PHOTOMETRY
THERMOCHEMICAL PROCESSES
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry