We describe theoretically the generation of ultrashort (subfemtosecond) pulses using high-order harmonics of a laser pulse with a time-dependent degree of ellipticity. The single-atom response is calculated by using a low-frequency strong-field approximation. Propagation effects are taken into account using a method going beyond the slowly varying envelope approximation. Propagation modifies significantly the results obtained in the single-atom response and, in certain conditions, makes the generation of one attosecond pulse possible. We discuss prospects for the observation of these ultrashort pulses. © 1997 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review A - Atomic, Molecular, and Optical Physics
Antoine, P., Milošević, D., L’Huillier, A., Gaarde, M., Salières, P., & Lewenstein, M. (1997). Generation of attosecond pulses in macroscopic media. Physical Review A - Atomic, Molecular, and Optical Physics, 56 (6), 4960-4969. https://doi.org/10.1103/PhysRevA.56.4960