MEASUREMENT OF MULTIPLE SURFACE TEST OBJECTS WITH FREQUENCY SCANNING INTERFEROMETER

摘要

A frequency scanning interferometer (10) is arranged for simultaneously measuring multiple surfaces (14, 15, 16) of a test object (12) through a wide range of expected offsets. Knowledge of the expected locations of the test surfaces is compared with a sequence of ambiguity intervals (U) based on a synthetic measurement wavelength (?eff) to center the test surfaces within the ambiguity intervals.