Advances in research and applications of optical aspheric surface metrology

Optical Systems using aspheric components (especially for free-form ones) have remarkable advantages over traditional spherical systems in that they can satisfy complicated requirements with simple optical-mechanical structures relying on abundant optional design parameters. Surface testing is an essential process for ensuring accuracy in manufacturing. Therefore, plenty of testing methods have been developed to meet varying testing demands of different types of surfaces at different stages in manufacturing. This paper summarizes the history of aspheric surface testing technology, classifies available techniques by whether they use interferometry, then introduces corresponding technical indexes, applicable conditions, research progress and applications. This paper highlights the high-precision interferometric methods, basic principles, optical layout and testing performances of every measurement method classified into Null and Non-null testing. The pros and cons of each method are compared, relative algorithms are introduced and precise adjustment methods are discussed.