A Measuring Method of Numerical Aperture of Optical Lens Based on Computational Imaging

Abstract

The invention discloses a computational imaging-based optical lens numerical aperture measurement method. The method includes the following steps that: a microscopic optical path system for numericalaperture measurement is constructed; the relative positions of a photographed object and a camera in the microscopic optical path system are adjusted, so that a microscopic image with a high dynamic range is obtained; a system magnification factor is calculated on the basis of to the size of the pixels of the camera and according to the size of the photographed object in the image; digital image processing is performed on the obtained image, so that a frequency diagram with a circular contour is obtained, and image processing is performed, so that the diameter of the circle is calculated; andthe numerical aperture of the lens is calculated according to the diameter of the circle and on the basis of the size of the pixels of a light sensing component, the system magnification factor, and an illumination light center wavelength. With the method of the invention adopted, the numerical aperture of any lens in life can be measured. The method has the advantages of simple operation processand high measurement precision. According to the method, the numerical aperture is obtained through calculation, human observation is rarely required, and the introduction of additional error can be effectively avoided.

Description

technical field [0001] The invention relates to the application field of lens numerical aperture measurement, in particular to a method and system for measuring the numerical aperture of an optical lens based on computational imaging. Background technique [0002] The numerical aperture NA is a very important technical index of the optical lens, reflecting the ability of the optical system to collect light, and in the microscopic lens, the numerical aperture also determines the minimum resolution capability of the system. [0003] In practical applications, the numerical aperture meter is usually used to measure the numerical aperture, which has problems such as cumbersome measurement process, low precision, manual observation, and high requirements for human observation ability. Especially when the numerical aperture is large, it needs to be operated with the aid of an auxiliary objective lens, and the operation process is more complicated. Moreover, the numerical aperture...

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Problems solved by technology

[0003] In practical applications, the numerical aperture meter is usually used to measure the numerical aperture, which has problems such as cumbersome measurement process, low precision, manual observation, and high requirements for human eye observation ability.

Especially when the numerical aperture is large, it needs to be operated with the aid of an auxiliary objective lens, and the operation process is more complicated

Moreover, the numerical aperture meter is only limited to measuring the numerical aperture of the microscope objective lens, which is not universal

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