Abstract
The case is considered of a weak Gaussian harmonic pulse of frquency passed through an atomic medium collinearly with an intense Gaussian laser pulse of frequency The harmonic beam may be amplified or deamplified according to the balance between stimulated emission and absorption. A simple analytic expression for the gain is derived in the tunneling limit of ionization. It predicts a positive (negative) gain for positive (negative) delay of the harmonic pulse with respect to the laser pump pulse. The gain may be significant and proportional to the delay for delays of a few laser periods, much shorter than the pulse envelopes. Possibilities for experimental observations are briefly discussed.
- Received 28 February 2001
DOI:https://doi.org/10.1103/PhysRevA.64.023419
©2001 American Physical Society