Optical system focal length measurement system and method

Abstract

The invention discloses an optical-system focal-length measuring system and a method. The system includes a laser point illumination positioning module, a light splitter, a point detection and positioning module, a standard plane mirror and goniometer equipment. The laser point illumination positioning module emits a laser at a focus of a measured optical system; the laser passes through the beamsplitter to enter the measured optical system, and then forms parallel light to exit; the parallel light is reflected to the measured optical system through the standard plane mirror to form collimation light by convergence; the collimation light is reflected through the beam splitter to form a reflection self-collimation focus; the goniometer equipment measures an included angle of the standard plane mirror and an optical axis of the measured optical system; the detection and positioning module positions the reflection self-collimation focus; a position change [delta]y which is of the reflection self-collimation focus and corresponds to an included-angle change [delta]theta of the standard plane mirror and the optical axis of the measured optical system is measured; and focal length of the measured optical system is calculated and obtained according to image height and focal-length relationships. The measuring system is accurate in focus positioning, and is suitable for use in installation, adjustment and detection of large-caliber long-focal-length optical-lenses of spatial optical remote sensors.

Description

technical field [0001] The invention relates to a system and method for measuring the focal length of an optical system, in particular to a method realized by combining laser confocal technology, self-collimation technology and the principle of precision angle measurement. It has important applications in the manufacture and inspection of optical systems, especially large-diameter long-focus lenses and lenses. Background technique [0002] Focal length is an extremely important optical parameter of an optical system. In the optical system, especially the long focal length and large aperture optical system, the accurate measurement of the focal length is particularly critical. Typical long focal length and large aperture optical systems include space optical systems and laser nuclear fusion optical systems. In the space optical system, the accurate measurement of the focal length of the lens is related to the accuracy of the ground resolution of the image, and is related to...

AI Technical Summary

Problems solved by technology

[0005] The technical problem of the present invention is: to overcome the deficiencies of the prior art, to propose a method for measuring the focal length of the optical system, and to solve the problem of low focus positioning accuracy when measuring the focal length of the optical system

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