Abstract

One of the most peculiar fetures of the harmonic spectra resulting from the interaction of an intense laser with a diluted gas, is the presence of a plateau at high harmonic intensities followed by an abrupt cutoff. In the tunnelling limit, the electron wavefunction overlaps with continuum states and therefore part of the wavefunction is not bound. It has been shown recently [1, 2] that this unbounded part of the wavefunction absorbs energy from the field during part of the cycle, and can release it, in the form of harmonic radiation when rescatering with the nucleus.

© 1994 Optical Society of America