Anomalous Behaviour of the Spectra in Young’s Double-Slit Interference Experiments

It is shown that an anomaly of the spectrum takes place in the interference field when Young’s double-slit interference experiment is illuminated by spatially coherent polychromatic light. Specifically, drastic spectral changes (i.e. the spectral shifts exhibit a rapid transition) occur in the vicinity of the dark fringes. The potential applications of this spectral anomaly are also considered.