The effect of clamping stress on the measured surface figure of optical glass BK7

Abstract This work probes the effect of clamping stress induced by pad block’s support surface (PBSS) shape error in measured surface figure of optical glass BK7. Under given PBSS topography measured by three coordinate machine, the clamping stress loaded on the workpiece and its effect on workpiece’s surface deformation was simulated by finite element method. Furthermore, the surface figure residual error (SFRE) in simulation was in good agreement with experimental results despite the measurement repeatability error.