A Method for Acquiring Time-Space-Frequency Information of Ultrashort Pulse Laser Far-field Focal Spot

Abstract

The invention discloses a method for acquiring time-space-frequency information of the far-field focal spot of an ultrashort pulse laser, and aims to solve the problem that the chromatic aberration of the existing transmission-type magnifying imaging system will cause the position of the far-field focal spot of the magnified imaging relative to the target point. A technical problem with changes in the distribution of far-field focal spots. The invention obtains the interference images at the focal plane position of the measured ultrashort pulse laser, at least one positive defocus position, and at least one negative defocus position through the interference imaging spectrometer; and then uses the interference spectrum imaging technology to process each interference image separately The corresponding focal spot intensity space-frequency information is obtained; based on all the focal spot intensity space-frequency information obtained, the two-dimensional information of the far-field focal spot space phase at each frequency in the measured ultrashort pulse laser is reconstructed by phase recovery technology ; Finally, according to the order of the frequency, the two-dimensional information of the spatial phase of all the far-field focal spots obtained is reconstructed to obtain the space-time-frequency information of the phase of the ultrashort pulse laser far-field focal spot.

Description

Technical field [0001] The present invention relates to a method of acquiring a short pulse laser far field focal spot time and space-frequency information. Background technique [0002] Since the ultra-short pulse laser has a wide spectral characteristic, the beam will produce a larger color difference during the transmission process (particularly the lens element) in the transmission process. This color difference will enlarge the target of the target of the target to several times diffraction limit, which is very disadvantageous to pursue the laser focus of the near-diffraction limit, and the introduction of the residual chromatic aberration also reduces the condensed ability of the far field focal spot. The precise measurement of ultra-short pulse laser far field focus is premise in the premise of precision physics experiments, and further optimization of the beam is formed by accurate measurement results, which is gradually formed to facilitate the optimum far field focus co...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the technical problem that the chromatic aberration of the transmission magnification imaging system in the prior art will cause the far-field focal spot distribution of the magnified imaging to change relative to the far-field focal spot position of the target point, and provides an ultra-short Method for Acquiring Time-Space-Frequency Information of Pulsed Laser Far-field Focal Spot

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