The study of surface quality has remained one of constant refinement and complication as techniques are developed to examine the tiniest of imperfections that may affect the performance of optical systems such as lasers. This book represents the most advanced studies in the application of new techniques for the objective measurement of surface quality to an industry standard. Historically, the quality of the surface of optical components was evaluated by visual comparison to other standard surfaces. The inconsistencies of this subjective method, and the emergence of increasingly powerful optical systems that are sensitive to even smaller imperfections, has driven the development of techniques reported in this book to provide higher accuracy and reliability through photoelectric measurement. These advances represent a major step forward in the objective measurement of surface quality, providing a foundation for more accurate and reliable quality control in the optics industry.