Abstract

Recent correlation–reflectometry techniques have demonstrated that loss in serial microoptic systems can be tracked with a spatial resolution of the order of a few micrometers.^1,2 We show here that the dispersion properties of individual components in these systems can also be measured from their reflection signatures. The method is based on Fourier transformation of the interferograms, as discussed by Bomberger and Burke.³ To illustrate the technique, we measured the dispersion in a 23-mm sample of single-mode fiber in the scanning Michelson interferometer of Fig. 1. The timedomain sweep is done with a PZT and cat’s-eye reflector and yields the signatures shown in Fig. 2. For the case of negligible transmission loss and balanced control arms, the transform of the crosscorrelation interferogram gives a modulus that represents the source frequency spectrum and an argument representing the phase of the frequency components. The phase function can be expanded about the frequency at peak intensity as

© 1988 Optical Society of America