Device and method for measuring point focusing ability of off-axis paraboloidal mirror

Abstract

The invention relates to a measuring device and a measuring method for the spot focusing capacity of an off-axis parabolic mirror. The measuring device is structured by including a He-Ne laser; a beam expander, a soft aperture slot and a off-axis parabolic mirror to be measured are arranged in turn along the direction of the emergent laser beam direction of the He-Ne laser; a standard cross hair and a micro objective are arranged in turn on the direction of the reflected beam of the off-axis parabolic mirror; the micro objective is arranged on the focus of the off-axis parabolic mirror; the focus is imaged on an area array CCD; the output end of the area array CCD is connected with a computer; the off-axis parabolic mirror is fixed on a five-dimensional electric adjusting frame. The measuring device has the characteristics of simple structure, convenient adjusting and high resolution factor; besides, the measuring device not only can obtain the size of the focal spot of the off-axis parabolic mirror, but also can obtain the two-dimensional distribution information of the intensity of the focal spot as well as can obtain the three-dimensional image information of the focal spot.

Description

technical field [0001] The invention relates to an off-axis parabolic mirror, in particular to a measuring device and a measuring method for the point focusing ability of the off-axis parabolic mirror. Background technique [0002] Off-axis parabolic mirror, under ideal conditions, when the incident light is strictly parallel to the optical axis, the reflected light is focused on the focal point. After the beam is reflected and focused, the focal spot is approximately regarded as an ideal point. Compared with the transmissive focusing method, it can eliminate the unfavorable phenomena such as dispersion and self-focusing of strong laser in the medium. In addition, it is durable to high-intensity laser. In recent years, it has been widely used in laser beam focusing, in the deflection path. Especially in femtosecond strong-field laser physics experiments, due to the high requirements for the focal spot of the laser point focus, it is necessary to obtain accurate and detaile...

AI Technical Summary

Problems solved by technology

Although the former is simple, intuitive, and highly sensitive, it can only measure the diameter of the focal spot and cannot obtain the energy distribution of the focal spot; the latter uses the scattered light of the focal spot on the object to obtain the information of the focal spot, which has a complex structure and is difficult to adjust , low resolution and high cost

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