A computer-based stroboscopic interferometric
microscope system for measuring the
topography of a microscopic vibratory object includes an interferometric
microscope equipped with a multiple-color (e.g., LED) or white-
light source, a mechanical scanning apparatus for varying the
optical path difference between the vibratory object and a
reference surface, a camera having a two-dimensional
detector array, and
digital signal processing apparatus for determining surface height from interference data. Interferograms for each of the
detector image points in the
field of view are generated simultaneously by scanning the object in a direction approximately perpendicular to the object surface illuminated stroboscopically while recording
detector data in
digital memory. Recorded interferograms for each image point are then transformed into the
spatial frequency domain by
Fourier analysis, and the surface height for each corresponding object
surface point is obtained by examination of the complex phase as a function of
spatial frequency. A complete three-dimensional image of the object surface is then constructed from the height data and corresponding
image plane coordinates. The three-dimensional image may be presented on a display or
hard copy or written to a storage medium.