Single attosecond soft-x-ray pulse generated with a limited laser beam

Abstract

The problem of obtaining a single attosecond pulse with high-order harmonics generation is considered. A method for producing an exciting light pulse with a time-dependent degree of ellipticity from a one-frequency linearly polarized laser pulse by means of linear optics is suggested. The whole of the field generated with a limited beam of this light in a gas target is calculated in the far zone. For this calculation we use an original method based on the time approach of a theory of high-order harmonic generation. Contrasted and intense (focused) single attosecond soft-x-ray pulses are calculated by suppression of the low-frequency part of the field to as many as 11 harmonics of exciting frequency. The possibility of suppressing the low-frequency part of the field with pinholes is shown.