Tunable narrow-band cw difference-frequency generation at 8.7 mu m was
demonstrated in silver gallium selenide (AgGaSe2) at room temperature
. The crystal was pumped by an injection-seeded Er/Yb-codoped fiber am
plifier at 1.554 mu m and a fiber-coupled diode-pumped monolithic ring
Nd:YAG laser at 1.319 mu m. The difference-frequency output was used
for high-resolution spectroscopy of sulfur dioxide (SO2). (C) 1996 Opt
ical Society of America