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Method and device for measuring focal distance of long-focal-length and large-aperture lens

A measurement method and a technology of a measurement device, which are applied in the direction of measurement devices, optical devices, and testing optical performance, can solve the problem that the measurement accuracy is limited by the angle measurement accuracy, and the application and detection of large-scale high-power laser systems that limit long-focus and large-diameter optical components Low precision and other problems, to achieve the effect of compact structure, fast detection and high detection accuracy

Inactive Publication Date: 2012-01-25
ZHEJIANG UNIV
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AI Technical Summary

Problems solved by technology

However, the test accuracy of this method is limited by the angle measurement accuracy. Under the current 1024×1024 image resolution, the focal length test accuracy is only 0.1%. Applications of High Power Laser Systems

Method used

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  • Method and device for measuring focal distance of long-focal-length and large-aperture lens
  • Method and device for measuring focal distance of long-focal-length and large-aperture lens
  • Method and device for measuring focal distance of long-focal-length and large-aperture lens

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Embodiment Construction

[0037] Such as figure 1 As shown, the implementation steps of the method for measuring the focal length of the long focal length and large diameter lens of the embodiment of the present invention are as follows:

[0038] 1) Sequentially irradiate the parallel light beams to the sampling points on one side of the lens under test, and collect the Moiré fringe image of the light Talbot effect from the other side of the sampling point of the lens under test;

[0039] 2) Obtain the moiré fringe movement amount of the moiré fringe image obtained by two sampling points whose distance is smaller than the diameter of the parallel beam;

[0040] 3) Acquiring the wavefront slopes of the measured lens corresponding to the two sampling point regions according to the moiré fringe movement in turn;

[0041] 4) Fitting the slopes of each wavefront to form a continuous fitting wavefront;

[0042] 5) The least square method is used to obtain the closest spherical surface of the fitting wave s...

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Abstract

The invention discloses a method and a device for measuring a focal distance of a long-focal-length and large-aperture lens. The method comprises the following implementation steps of: (1) irradiating sampling points on one side of a lens to be tested by parallel light beams in sequence and acquiring a moire fringe image of a Talbot effect of transmitted light; (2) acquiring moire fringe movementamount of a plurality of groups of moire fringe images of two sampling points with distance less than diameter of the parallel light beams; (3) acquiring wave front slope of two corresponding sampling point regions of the lens to be tested in sequence according to the moire fringe movement amount; (4) fitting each wave front slope to form a continuous fitting wave surface; and (5) acquiring the closest spherical surface of the fitting wave surface by using the least square method to acquire the spherical radius of the closest spherical surface. The device comprises a parallel light beam transmission unit, a moire fringe generation unit, an image acquisition unit and an image processing unit. Through the method and the device, the focal distance measurement of the long-focal-length and large-aperture lens can be effectively realized; and the method and the device have the advantages of high measurement accuracy, high adaptability and easiness and convenience in operation.

Description

technical field [0001] The invention relates to the field of optical instrument detection, in particular to a method and device for measuring the focal length of an optical element with a long focal length and a large diameter. Background technique [0002] Large-scale high-power laser systems generally have a large number of optical components. For example, domestic ICF laser drivers, the US National Ignition Facility (NIF) and the French Mega-Joule Laser Project (Mega-Joule Project) all use thousands of various optical components; In my country's Shenguang III system, there are only 8,000 optical components of various calibers above 400mm×500mm, of which there are about 1,000 long focal length systems for spatial filtering and focusing. Therefore, the long-focus and large-aperture optical component system is an important part of the optical components in the large-scale high-power laser system. To realize the precise operation of the large-scale high-power laser system, it ...

Claims

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Application Information

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IPC IPC(8): G01M11/02G01B11/255
Inventor 侯昌伦
Owner ZHEJIANG UNIV
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