Abstract

The efficiency for generating ultra-high harmonics (HHG) in intense laser fields has been studied as a function of many parameters, such as the density or composition of the nonlinear medium; the wavelength and intensity of the light; and the incident polarization.^1-3 The characteristic "plateau," or slow variation in efficiency over many high harmonics, is now known to depend on these parameters in a manner consistent with the predictions of some recent theories, in which harmonics are due to inelastic rescattering of field-ionized electrons driven against their parent ion by the laser field.^4-6

© 1994 Optical Society of America