Method for generating plesiochronous higher harmonic or X-ray radiation through laser secondary excitation

Abstract

The invention relates to a method for generating higher harmonic or soft X-ray, in particular to a method for generating plesiochronous higher harmonic or soft X-ray radiation through laser secondary excitation. In the method, secondary focusing is performed on a focused incident laser beam by using an ellipsoidal reflection cavity; a hollow capillary which is filled with flowing working media is collinearly fixed along with a long axis of the ellipsoidal reflection cavity; an incident driving laser beam is focused at one focus of the ellipsoidal cavity and then is secondarily focused at another focus of the ellipsoidal cavity after being reflected by the inner surface of the ellipsoidal cavity, so the driving laser excites higher harmonic relational radiation in the soft X-ray range for two times in the working media at the two focuses of the ellipsoidal cavity; at the same time, the propagation time of the driving laser between the two focuses is as same as that of the higher harmonic between the two focuses, so coherent reinforced output under the condition that the quasi-phase speed of the driving laser is matched with that of the radiation light is realized; and the separated transmission of the higher harmonic or soft X-ray beam and the driving laser beam at the output end is realized in a laser beam large-angle incident laterally driving mode.

Description

technical field [0001] The invention relates to a method for generating quasi-synchronous high-order harmonics or coherent soft X-ray radiation through laser secondary excitation. The generated coherent soft X-ray radiation is in the range of tens of electron volts to more than one thousand electron volts. The coherent soft X-ray beam (source) can be applied to engineering technology industries such as micro-nano lithography or micro-nano processing, analysis and diagnosis of biomedicine and material science, ultrafast dynamics of atoms and molecules, and extremely high time-resolved spectroscopy. Basic research and many other fields and industries. Background technique [0002] In recent years, the high-order harmonics driven by ultrashort pulses have unique properties such as short radiation time, narrow frequency band, and adjustable wavelength. They are extremely ultraviolet (EUV) and soft The extremely effective way of X-rays makes it widely used in various fields, and...

AI Technical Summary

Problems solved by technology

[0010] The inventions and technologies mentioned above have made certain contributions to improving the harmonic brightness, but the absorption of EUV light or soft X-rays by the plasma, the phase matching between the harmonic field and the driving laser still need to be further optimized, and the harmonic The conversion efficiency is always not high; and the harmonic output direction is the same as that of the driving laser, and it is necessary to use a filter to filter out the driving laser to detect the generated EUV light, which increases the cost and difficulty of the experiment

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