Investigation of Aberration for Optical System in Integral Stereolithography System

Optical imaging system is a key component for dynamic pattern generator in integral Stereolithography (SL) system, and the performance of the optical imaging system influences building accuracy and resolution of the integral SL system. The larger the aberration of the optical imaging system, the larger the dimension errors of objects built with the integral SL system, and larger aberration will make it impossible for the integral SL system to fabricate small objects with micro/meso structures. In order to assure the integral SL system has enough ability to build small object with micro/meso structures, the optical imaging system is established, and the aberration of the optical imaging system is investigated with ZEMAX. The optical imaging system consists of two components. The component 1 consists of 3 positive lenses, and the component 2 is made up of a negative lens, two positive lenses and a aperture. Aberrations analysis results shows that there are some residual spherical aberrations, off-axis spherical aberration and coma, and sagittal coma is larger than the meridional coma. The largest coma value of the optical imaging system is 0.08mm, and the average dispersion spot size is 0.04mm, and. The maximum astigmatism is 0.2 mm and the maximum field curvature is 1.4mm, the maximum distortion is less than 2%. The resolution is 0.05mm. Aberrations analysis results indicate that the performance of the optical imaging system can meet the requirements of the integral SL system.