We describe a signal-processing method for determining the center position of a white-light fringe signal. This is achieved in two steps. First, the center of gravity of the signal power is calculated to better than half a fringe period. Second, a synchronous sampling with four samples per fringe period is used to calculate the phase of the zero fringe. The theoretical analysis and experimental results show that the proposed signal processing is simple to operate, fast, accurate, and extremely noise resistant.
© 1992 Optical Society of America
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