Abstract
We study high-order harmonic generation in the general case of absorbing and dispersive atomic gas media. For ultrashort laser pulses, the harmonic conversion efficiency tends to a limit mainly imposed by the harmonic reabsorption in the gas. This limit, independent on the gas density, is the same for both the case of a loosely focused beam or a beam guided in a gas-filled hollow-core fiber. Under optimum conditions, we measured the highest conversion efficiency to date for the 15th harmonic generated in xenon using a 40 fs, 1.5 mJ, 800 nm pulse at a 1 kHz repetition rate.
- Received 21 September 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.1668
©1999 American Physical Society