Laser-induced gratings in free jets. I. Spectroscopy of predissociating NO[sub 2]

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Journal of Chemical Physics; (United States)

DOI:https://doi.org/10.1063/1.464895· OSTI ID:6697991

Butenhoff, T J; Rohlfing, E A ^[1]

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

We use two-color laser-induced grating spectroscopy (LIGS) to obtain double-resonance, absorptionlike spectra of jet-cooled NO[sub 2] below and above the threshold for predissociation at 398 nm. The grating-laser frequency is tuned through the dissociation threshold while the probe-laser frequency is fixed to a specific rotational line of an isolated, cold vibronic band well below threshold. The signal beam diffracts off the ground state depletion grating formed when the grating laser excites a transition out of the rotational level selected by the probe laser. The above-threshold spectra observed for NO[sub 2] indicate that, under collision-free conditions in the free jet, the LIGS spectrum maps the square of the absorption spectrum. We determine predissociation lifetimes from LIGS linewidths and discuss the temporal decay of the induced grating as a function of its orientation with respect to the jet axis. Finally, we consider the effects of phase matching on two-color LIGS in the forward geometry and derive expressions for the variation in signal-beam angle and for the phase matching bandwidths for experiments in which the frequency of either the grating or probe laser is scanned.

• OSTI ID: 6697991
• Journal Information: Journal of Chemical Physics; (United States), Journal Name: Journal of Chemical Physics; (United States) Vol. 98:7; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION
CHALCOGENIDES
COLOR
COOLING
DISSOCIATION
DOUBLE RESONANCE METHODS
ELECTROMAGNETIC RADIATION
ENERGY
GRATINGS
JETS
LASERS
LIFETIME
LINE WIDTHS
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PREDISSOCIATION
RADIATIONS
SORPTION
THRESHOLD ENERGY
ULTRAVIOLET RADIATION