Controlling the shape of Talbot bands' visibility

Abstract

We present a theoretical model to predict the sensitivity variation versus optical path difference (OPD) in Fourier domain spectral interferometry using configurations which produce Talbot bands. Such configurations require that the two interfering beams use different parts of the diffraction grating in the interrogating spectrometer. So far, the power distribution within the two beams in a Talbot bands experiment was considered uniform. In this report, we show that by manipulating the power distribution within the two interfering beams, the OPD value where maximum sensitivity is achieved can be conveniently tuned, as well as the sensitivity variation with OPD. Furthermore, creating a gap between the two beams leads to adjustment of the minimum detectable OPD value, while the width of the beams determine the maximum detectable OPD value. These features cannot be explained by theoretical models published so far involving spectrometer resolution elements only, while such features are correctly predicted by the model presented here.