Modeling and analysis of transmission optical centering device

The image quality of an optical system is limited not only by its inherent design aberrations, but also by the fabrication and assembly errors of its elements. Any small decentration error of an optical lens has a significant effect on the quality of the image it produces. In this paper, a simple method which employs skew ray tracing is described for calculating the decentration error resulting from the surface tilt of a measured optical lens by using transmission optical centering device. We address two important topics: (1) the decentration error and the spot circle radius are related by a linear approximation when the decentration error is small; and (2) an approximate value of the decentration error can be obtained by taking the first-order differentiation of the mathematical expression for the decentration error when the surface angle of tilt is small.