Tolerance analysis and test of focus' coincidence with last surface's curvature center for reference lenses

Reference lenses play an important role in test of spherical surfaces. In this condition, the ray reflected from the tested spherical surface goes the same way as that from the last surface of the reference lenses. If the two rays go different way, the focus of the reference lenses is not coincidence with its last surface's curvature center, and system error is produced. The deviations between the focus and the curvature center of the last surface for a series of reference lenses are studied in this paper.