Discrete fringe pattern to reduce the resolution limit for white light interferometry

In white light interferometry, the measurement resolution is relatively lim ited by the coherence length of the light source, usually in tens of fringe s. In this work, a simple, real time technique is developed, to transform t he output signal into a discrete fringe pattern on a real time basis, with a sharp and dominant central fringe, which effectively reduces the relative resolution limit to a subfringe level and thus possessing a great potentia l for high-precision measurements. (C) 1999 Elsevier Science B.V. All right s reserved.