ABSTRACT: In this project, research into optimizing a radius of curvature measurement system for FEL cavity mirrors was undertaken. The system is characterized by significant diffraction effects due to the use of a He-Ne laser beam as a light source. Optimization of image formation through diffraction control was studied in both computer simulations and the physical system. Radius of curvature measurements of many FEL cavity mirrors were conducted. The results show the method to be theoretically sound and capable of producing measurements of long ROC mirros accurate to within 0.5%.
Here is the thesis in PDF: Springer Thesis