A method to generate a single sub-50-as pulse by employing a 5-fs laser pulse with intensity above the saturation intensity, was proposed. The neon target medium of 0.5 mm length and 5 Torr pressure, was placed 10 mm beyond the laser focus. Harmonic radiation from neon atoms, was obtained by solving the time-dependent Schrödinger equation coupled with Maxwell equations. The results show that the positive chirp contained in the broad continuum radiation can be compensated by an x-ray filter with a negative group delay dispersion in the spectral region of interest.

Kim, K.T.Kim, C.M.Baik, M.G.Umesh, G.Nam, C.H.2026-02-05Single subPhysical Review A - Atomic, Molecular, and Optical Physics, 2004, 69, 0.208333333333333, pp. 1-5180510502947https://doi.org/10.1103/PhysRevA.69.051805https://idr.nitk.ac.in/handle/123456789/279592004Harmonic generationHigh energy lasersIonizationLight absorptionLight propagationLight transmissionMaxwell equationsNeonOptical filtersRefractive indexX raysHarmonic radiationLinear frequency chirpSingle attosecond pulsesX ray filtersLaser pulsesA method to generate a single sub-50-as pulse by employing a 5-fs laser pulse with intensity above the saturation intensity, was proposed. The neon target medium of 0.5 mm length and 5 Torr pressure, was placed 10 mm beyond the laser focus. Harmonic radiation from neon atoms, was obtained by solving the time-dependent Schrödinger equation coupled with Maxwell equations. The results show that the positive chirp contained in the broad continuum radiation can be compensated by an x-ray filter with a negative group delay dispersion in the spectral region of interest.