Method for inhibiting hole blocking effect of vacuum filter using near uniform strong magnetic field

Abstract

The invention relates to a method for inhibiting the hole blocking effect of a vacuum filter using a near uniform strong magnetic field. The method is used for solving the problem of existing traditional vacuum filter that complete filtering is unavailable since the free-diffusion metal plasma generated by the focal spot wing (hereinafter called 'skirt') after focusing of high-power pulse laser acting on the edge of a filtering component (hereinafter called 'small hole') hinders the passage of the back edge of the laser pulse. In the invention, based on traditional vacuum filter, a near uniform strong magnetic field with certain magnitude is applied to the small hole, the metal plasma generated on the edge of the small hole by the focusing skirt of the high-power pulse laser moves in the direction of magnetic induction line, thus the plasma density at the center of the small hole is reduced, the hole blocking effect of traditional vacuum filter is effectively solved, and a good filtering effect of traditional vacuum filter is realized. The method provided by the invention has the characteristics of convenience in adjustment, simplicity and high efficiency, high practicability and the like.

Description

technical field [0001] The invention relates to the field of large-scale high-power pulsed laser devices and the field of plasma, in particular to a method for suppressing the hole blocking effect of a traditional vacuum filter. Background technique [0002] In the field of high-power pulsed laser devices, the inhomogeneity and small-scale self-focusing effect of amplifiers at all levels in the pump light and signal light have become the main reasons affecting the quality of the near-field beam, so the uniformity of the laser near-field spot can be improved. Performance plays an irreplaceable role in improving the load capacity of high-power pulsed laser devices. [0003] In the past few years in the research of petawatt-level high-power pulsed laser devices, despite the gradual improvement of the beam quality of pump light and signal light at all levels, the gradual improvement of the damage threshold of various optical components and the corresponding AO active compensatio...

AI Technical Summary

Problems solved by technology

The "blocking effect" of the traditional vacuum filter refers to the plasma generated by the interaction between the "skirt" of the high-power pulsed laser and the edge of the small hole due to free diffusion to the center of the small hole, blocking the high-power pulsed laser The trailing edge of the pulse continues to pass through the small hole, making the traditional vacuum filter unable to filter perfectly

[0006] Chinese patent 201320775747.5 discloses a spatial filter with a low cut-off frequency. Although the utility model patent can reduce the plugging effect of the traditional vacuum filter by installing a Bragg volume grating in front of the traditional vacuum filter, the Bragg volume grating used in this patent The grating not only has a low damage threshold, but also has the problem of its own size limitation

This is not suitable for large traditional vacuum filters with large laser spots and high energy density of injected lasers, and installing Bragg volume gratings in front of traditional vacuum filters will introduce certain aberrations, which is not suitable for subsequent compression of high-power pulsed lasers. The process will have additional effects

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