We present a new interferometer system devised for surface-profile metrology with multiple two-point-diffraction sources that are made from a pair of single-mode optical fibers. The diffraction interferometer system performs an absolute profile measurement by projecting multiple fringe patterns on the object surface and then fitting the measured phase data into a global model of multilateration. Test measurement results demonstrate that the proposed profiling method is suited for rough surfaces with excessive surface irregularities, which are difficult to measure with conventional two-arm interferometers.
© 2003 Optical Society of America
(050.5080) Diffraction and gratings : Phase shift
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4630) Instrumentation, measurement, and metrology : Optical inspection
Byoung-Chang Kim and Seung-Woo Kim, "Absolute interferometer for three-dimensional profile measurement of rough surfaces," Opt. Lett. 28, 528-530 (2003)