Attosecond pulse measuring method and device thereof

Abstract

The invention discloses an attosecond pulse measuring method and a device thereof. The method comprises the following steps: enabling a beam of weak femtosecond pulse to act on the generation processof attosecond pulse to be measured, so as to change the accumulated phase of ionized free electrons in a free state in the generation process of the attosecond pulse to be measured and to carry out the perturbation of the attosecond pulse frequency spectrum to be measured, wherein the weak femtosecond pulse is a femtosecond pulse with the intensity being within a preset intensity range; adjustingthe relative time delay between the weak femtosecond pulse and a driving field used for generating the attosecond pulse to be measured to obtain a two-dimensional trace graph of the attosecond pulse frequency spectrum to be measured changing along with the relative time delay; and extracting complete time domain structure information of the attosecond pulse to be measured from the two-dimensionaltrace graph through a reconstruction algorithm. According to the method, a beam of extra weak femtosecond pulse is introduced to carry out perturbation on the generation process of a single attosecondpulse, a two-dimensional diagram of single attosecond frequency spectrum changing along with time delay is obtained by changing relative time delay between the two beams of pulse, and finally the time structure information of the single attosecond pulse is extracted from the two-dimensional diagram through a PCGPA algorithm.

Description

technical field [0001] The present invention relates to the field of ultrafast laser technology, and more specifically, to a method and device for measuring attosecond pulses. Background technique [0002] Due to its extremely high time resolution, single attosecond pulses based on high-order harmonic extraction have always been an important means to detect ultrafast dynamical processes of atoms and molecules, so the complete measurement of attosecond pulses is very important. However, its ultra-short time scale makes it difficult for us to directly measure it experimentally. The current mainstream measurement method is to use the attosecond pulse to interact with atoms to generate a single photon ionization process, thereby converting the frequency domain information of the single attosecond pulse into the photoelectron spectrum. Then a beam of infrared is introduced to fringe-modulate the photoelectron energy spectrum, and the delay between the single attosecond pulse and...

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Problems solved by technology

[0004] In view of the defects of the prior art, the purpose of the present invention is to solve the technical problem that the existing attosecond pulse measurement method (FROG-CRAB technology) uses a central momentum approximation that causes errors in the measurement of the attosecond pulse results

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