New method for detecting transient gain (or loss) in pulsed gas discharges

A pulsed argon discharge inside a CW-laser cavity is used to modulate the CW-laser output via the transient gain/loss at various lasing wavelengths. Under short-pulse excitation (
\sim 0.6 \mu
s), gain is found at four Ar(II) lasing lines, but losses are observed at 4880 and 5017 Å. A similar diagnostic device with broad-band capabilities and based on an ion-laser-pumped dye laser is proposed.