Optical testing: a review and tutorial for optical engineers

Optical instruments are precision tools and must be made to very high tolerances. Deviations from the correct shape of individual lens surfaces of fractions of a micrometre can result in an unacceptable performance level in the final instrument. It is essential, therefore, that manufacturers of optical instruments can test the individual components of their instruments to these very high tolerances. It is also necessary for both manufacturers and users to be able to test the final performance of the instruments. This review paper describes both manufacturers’ and users’ tests. It is aimed at optical test engineers and emphasizes the practical aspects of optical testing rather than the theory. Mathematical equations are kept to a minimum: a comprehensive list of references allows the reader to obtain more detailed information if required.