Specification and Control of Mid-Spatial Frequency Wavefront Errors in Optical Systems

This paper is an introduction to the specification and tolerancing of Mid-spatial frequency (MSF) ripple or waviness. We begin with an introduction to the definition of ripple, spatial frequencies, and MSF ripple as a class of surface error (as opposed to figure or form, roughness, and surface imperfections or defects.) We then cover the derivation of spatial frequency bands of interest, specifications methods and notations, and relative amplitudes for typical manufacturing processes.