Use of three detuned lasers to generate isolated attosecond pulses

The dynamics of a one-dimensional atom driven by three-laser fields is investigated. The total electric field is made up of a fundamental laser field of intensity  W cm−2 and wavelength λ = 820 nm and two weak lasers with larger wavelengths. The intensity of the two weak fields is with k = 0.25. The frequencies of the weak fields are and , with and . The three lasers have a Gaussian envelope of 72 fs FWHM. It is shown, by numerical computation and using the semiclassical theory of high-harmonic generation, that the atom interacting with this combined field is able to emit an isolated attosecond burst of radiation.