Abstract
The results of study of high-order harmonic generation from the surfaces of various materials by using femtosecond radiation with a variable chirp are presented. The analysis and optimization of radiation conversion into harmonics up to the fifteenth order (lambda = 52.9 nm) are carried out. It is shown that the maximum conversion efficiency is realized for the surfaces of silver and glass. The wavelength of harmonics can be tuned over the 2-nm range by changing the chirp of the radiation converted.