A method for measuring and adaptively correcting lens center thickness based on the chromatic confocal principle

Abstract

Optical systems are widely used in aerospace, life sciences, civil livelihood and other fields. The lens is one of the most common components in optical systems, and its centre thickness is an important parameter in material characterization and manufacturing process, which directly affects the performance and function of optical components. In this paper, based on the chromatic confocal principle and laser interference technology, we propose a method applied to the measurement and adaptive correction of lens centre thickness, aiming to solve the problem of lens centre thickness measurement error. We successfully built an adaptive error correction system and proposed a translation correction algorithm and a tilt correction algorithm. This method not only can accurately measure the lens thickness but also can adaptively compensate for the measurement error caused by the lack of accuracy of mechanical elements or motion mechanisms through the spatial attitude correction of the element to be measured. The experimental results show that this method has obvious advantages in the translation error correction and tilt error correction of the lens. After the translation correction, the measurement accuracy of the lens is improved by about 75.21%; after the tilt correction, the measurement accuracy of the lens is improved by about 71.48%.

Keywords

• Chromatic confocal
• Laser interference
• Centre thickness inspection
• Adaptive calibration
• Translation correction method
• Tilt correction method