Attosecond-chirp compensation with material dispersion to produce near transform-limited attosecond pulses

The duration of attosecond pulses, produced through high harmonic generation from gaseous atoms, was found to be much longer than the transform-limited duration. The inherent attosecond chirp existing in the temporal structure of the attosecond pulses was analysed to obtain a scaling factor in terms of laser intensity and wavelength. We explored the attosecond chirp compensation using various materials with negative group delay dispersion to cover different spectral ranges. From numerical simulations based on the time-dependent Schrodinger equation, we showed that 38 as isolated attosecond pulses could be produced by applying intense few-cycle mid-infrared laser pulses after compensating for the attosecond chirp in Xe.