| 摘要 |
An optical system for measuring the front and back surface topography of transparent objects with substantially parallel surfaces includes an interferometer, an electronic camera, and digital signal processing means for determining surface height from interference data. The several disclosed methods of the invention permit the mathematical separation of the interference contributions due to the multiple reflections from the two parallel surfaces of the object. These methods involve relatively simple procedures, such as reversing the orientation of the object between two successive interference measurements, followed by mathematical analysis or calculations that may be readily performed by computer. The preferred apparatus includes a tunable laser source that is used to remove undesirable artifacts and improve the quality of the final image.
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