An expression is proposed for a threshold discriminating between classical quasi-steady-state amplification and a strong pumping regime where a new dynamic behavior shows up in plasma-based extreme-ultraviolet (XUV) lasers. The criterion derived is applied to laser systems currently investigated in various laboratories. It is found that only high-gain XUV laser systems can be driven in that dynamic regime, associated with Rabi oscillations. For those systems, the small-signal dynamic gain accounting for the exponential amplification of the laser intensity is shown to be significantly smaller than the adiabatic value usually inferred from numerical simulations.
© 2013 Optical Society of America
Lasers and Laser Optics
Original Manuscript: May 7, 2013
Manuscript Accepted: June 6, 2013
Published: July 10, 2013
Olivier Larroche, Limin Meng, Andréa Le Marec, and Annie Klisnick, "Inversion density threshold for Rabi oscillations and modified small-signal gain in extreme-ultraviolet lasers," Opt. Lett. 38, 2505-2508 (2013)