Abstract

Conventional optical methods of surface profiling are limited in the range of surface heights that can be accurately measured due to phase ambiguity errors on steep local slopes. Instruments that have been developed thus far to avoid the problems with local slope typically suffer from poor measurement height resolution and slow measurement speeds. Contact profilometers such as stylus-based instruments suffer from slow measurement speeds, especially when two-dimensional scans of the surface are required. Stylus tips can also scratch delicate surfaces during the course of the measurement. A new method of optical, non-contact profiling of rough surfaces is described that utilizes interferometric techniques as well as digital signal processing algorithms to produce fast, accurate, and repeatable three-dimensional surface profile measurements.

© 1992 Optical Society of America