Method and system for weakly coherent optical detection of lens internal deformation

Abstract

The invention discloses a weak coherent optical detection method and system for internal deformation of a lens. Use OCT to collect the interference spectrum of each lens surface before and after the lens deformation; extract and obtain the complex signal in the depth domain; based on the intensity signal in the depth domain, perform surface positioning of each lens surface with micron precision, and obtain the pixel position and sub-pixel position of each lens surface ; Based on the depth domain phase signal, detect the internal deformation of the lens with nanometer precision; analyze the spectral domain phase of each lens surface based on the depth domain complex signal to compensate the wrapping amount of the depth domain phase, and expand the range to the micron level. The invention solves the problem that the measurement range and the precision cannot be taken into account simultaneously in the traditional method, realizes the large-range and high-precision non-destructive detection of the internal deformation of the lens, optimizes the problem of artifacts, and improves the stability of the positioning of each lens surface.

Description

technical field [0001] The present invention relates to a lens inspection method and system in the field of lens industry inspection, and more particularly relates to a large-scale and high-precision lens internal deformation measurement system and method associated with optical coherent imaging. Background technique [0002] With the progress of society and industry, the application scenarios of lenses are developing rapidly. As an imaging system, the lens needs to maintain sufficient imaging quality in changing external environments (such as mechanical force, temperature, humidity, acid-base, etc.). Extreme environments will change the internal deformation of the lens, which will cause changes in the imaging performance of the lens. Quantitative measurement of the internal deformation of the lens is required to evaluate the reliability of the lens. [0003] At present, a variety of technologies have been applied to the surface topography detection of a single lens, such a...

AI Technical Summary

Problems solved by technology

There are some problems in the existing OCT lens measurement method. On the one hand, because the lens has a smooth surface, the scanning beam will have obvious reflection when passing through. This part of the reflection component will form lens artifacts and hinder the recognition of the lens surface. This problem It is especially noticeable in multi-lens systems; on the other hand, the structural resolution of existing OCT devices is generally 1-20um, which cannot meet the accuracy requirements for distinguishing the internal deformation of the lens, and the high-precision phase OCT is due to the wrapping effect of the phase. , resulting in its range being limited to half of the center wavelength of the scanning light, forming a range gap from 1 / 2 wavelength to structural resolution

Images