Reconstruction of laser envelopes by infrared field dressed single photoionization

Abstract

Attosecond pump–probe experiments are conceived as a powerful tool to investigate ultrafast electron dynamics. To accurately probe electron motion, the ultraviolet (UV) and infrared (IR) fields should be carefully characterized. Here, we theoretically propose a method for reconstruction of laser envelopes by IR-field-dressed single-photon UV ionization of hydrogen. By simulating the photoelectron spectrum for different time delays between the IR and UV fields, we show that the envelope of the UV field can be retrieved from the central peak of the photoelectron spectrum when the IR and UV fields separate completely in time. With the retrieved envelope of the UV field, the envelope of the IR field can be further characterized by the delay-dependent intensity ratio between the sideband and central peaks. Our method is robust for reconstructing the envelope of more complex laser fields.