Broad-band gain in optically pumped S2

The
B^{3} \Sigma-_{u} \rightarrow X^{3}\Sigma-_{g}
system of S
2
has many of the characteristics required of a tunable laser: a broad fluorescence spectrum and a Franck-Condon shift between the
B
and
X
states. In this paper, the
\upsilon' = 4
level of the
B^{3} \Sigma-_{u} \rightarrow X^{3}\Sigma-_{g}
system of S
2
is pumped by the absorption of the 308 nm XeCl excimer radiation. Rare gas-S
2
collisions redistribute the population among the
\upsilon'
levels, and the subsequent emission contains intense bands throughout much of the neat UV and visible region of the spectrum. Broad-band gain is reported on two blue-green bands (2,17) and (3,18) populated by rare gas relaxation. Absorption is reported on the near UV bands
\upsilon' = 0 \rightarrow \upsilon" \rightarrow 6,7,8
where the lower levels are filled by the transient population cascading down the
X
state manifold. A fluorescence study is presented which examines the potential advantages and limitations of this system.