A TWO-PHOTON OPTICALLY PUMPED MOLECULAR GAS VISIBLE LASER

by
C. R. Quick, Jr., J. H. Glownia, J. J. Tiee and F. L. Archuleta
The University of California
Chemistry Division
Los Alamos National Laboratory
P. 0. Box 1663
Los Alamos, New Mexico 87545
ABSTRACT
Recent investigations of the multiphoton ionization (MPI) spectrum of
gaseous ammonia have led to the discovery of a novel two-photon pumped mole-
cular gas electronic transition laser. Resonant, two-photon electronic
excitation of NH3 in the near uv (-305 nm) leads to the first observation of
fluorescence from NH3 excited states (B and C'), and, at higher pressures,
to lasing action (-570 nm) between numerous C' and A state vibronic levels.
A frequency-doubled Nd:YAG pumped dye laser (a few mJ) is focused into a cell
containing NH3 (or ND3), Stimulated emission is observed in the forward and
backward directior at NH3 pressures greater than -200 torr, without external
mirrors to provide feedback. Conversion efficiencies (output NH3 pulse
energy/input pulse energy) as high as 2% have been observed.
*
Work performed under the auspices of US DOE.
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United States Government or any agency thereof,                    01sm ul                W