Measurement mechanism of lens focal length, measurement method and thereof and optical quality evaluation method

Abstract

The invention relates to a device and a method for measuring lens focal length as well as a method for evaluating optical quality, wherein the device for measuring the lens focal length is composed of a plane mirror, a lens to be measured, a point light source, a vertical incision, a one-dimensional precise flat movable guide rail, a laser distance measuring instrument, a CCD detector and a display, and the method for measuring the lens focal length is as follows: (1) adjusting the autocollimation of the point light source and the lens to be measured; (2) adjusting the plane mirror to make the transflective convergent beam enter the CCD detector; (3) measuring the focal depth of the lens to be measured; (4) measuring the distance L from the point light source to the geometric main plane of the lens to be measured; (5) calculating the focal length f = L + d of the lens to be measured, and the d is the distance between the geometric main plane of the lens and the optical main plane. The optical processing quality of the lens to be measured is qualitatively evaluated through the observation of shape of the far-field focal spot. The device and the method are applied to the measurement and evaluation of the small-bore short-focus and large-bore long-focus lens, and have the advantages of the intuitionism, the high measuring precision and the simple mechanism.

Description

technical field [0001] The present invention relates to a lens, in particular to a lens focal length measurement device, a measurement method and an optical quality evaluation method. The method is suitable for the measurement and evaluation of small aperture short focal length and large aperture long focal length lenses. The relative error of focal length measurement is small and significant. The measurement accuracy of the large aperture and long focal length lens is improved. Background technique [0002] With the rapid development of large-scale laser fusion devices (ICF), the spatial filter lens used in the device has a diameter of 0.3 to 0.5 meters and a focal length of tens of meters. However, the processing and measurement accuracy of the existing large-aperture long-focus lens is only 1-5‰, and the nominal measurement error of the long-focus lens based on the Longji grating Talbotta effect is 0.15%. The result is affected by the calibration error, which is not suit...

AI Technical Summary

Problems solved by technology

However, the processing and measurement accuracy of the existing large-aperture long-focus lens is only 1-5‰, and the nominal measurement error of the long-focus lens based on the Longji grating Talbotta effect is 0.15%. The result is affected by the calibration error, which is not suitable for the measurement of large aperture and large F number optical elements

The spatial filter is limited by lens processing and measurement, the structure of the adjustment mechanism is complicated, and installation and maintenance are difficult. Therefore, it is necessary to develop a high-precision measurement method for large-diameter long-focus lenses to achieve high-precision measurement of the lens focal length and simplify the lens adjustment mechanism and installation adjustment methods. Improve institutional stability

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