Abstract
The residual stress generated from fabrication processing may cause the lens surface profile deform. Thus, measuring the residual stress of the lens during fabrication processing is needed. In this thesis, a method for measuring axisymmetric residual stress of the lens was proposed so that it is possible to optimize the fabrication parameters to reduce the residual stress of the lens in advance. Integrated photoelasticity can be used to measure the axisymmetric thermal residual stress in an axisymmetric specimen. However, the axisymmetric residual stress distribution produced by the traditional fabrication methods for the large mirrors is complicated so that the existing integrated photoelastic methods cannot be used. In this thesis, by using the stress equilibrium, improved linear approximation integrated photoelasticity (ILAIP) and improved nonlinear algorithm integrated photoelasticity (INAIP) were presented to calculate the axisymmetric residual stress in general cases. In this thesis, the calculation error of implementing ILAIP was first investigated by simulation and the applicability of ILAIP was then verified. Furthermore, the calculation error by using the ILAIP can be effectively reduced by using the INAIP.