Open Access Presentation + Paper
9 September 2021 Surface slope tolerances: the transition from geometric raytracing to scalar wave theory
Author Affiliations +
Abstract
In a previous presentation, the author presented a method of tolerancing mid-frequency surface ripple, based on a sensitivity parameter that related the slope error on the surface to the ray deviation at the image plane. The method established an upper allowable limit for the slope error on the surface. Because the analysis method was based on geometric raytracing, it included no consideration of scale. (Snell’s law is Snell’s law, regardless of the size of the feature.) Although the intention was to apply this design method only to macroscopic surface features, the notion of a slope limit without a scale limitation raises the question as to the region of validity, i.e., when do we need to take diffraction or scatter into account? In this presentation, we examine the transition between geometric raytracing and scalar diffraction theory. This is entirely analogous to the transition between the geometric model of a Ronchi test and that of a diffraction-based, lateral shear interferometer.
Conference Presentation
© (2021) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
John R. Rogers "Surface slope tolerances: the transition from geometric raytracing to scalar wave theory", Proc. SPIE 11813, Tribute to James C. Wyant: The Extraordinaire in Optical Metrology and Optics Education, 118130Q (9 September 2021); https://doi.org/10.1117/12.2567548
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Diffraction

Tolerancing

Wavefronts

Bessel functions

Ray tracing

Geometrical optics

Reflectivity

Back to Top