Patent attributes
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.
