Spectra in nested Mach–Zehnder interferometer experiments

Highlights: • Recent nested Mach–Zehnder interferometer experiments are analyzed within the framework of ordinary quantum mechanics. • The analysis explains the absence of certain peaks in the power spectra studied in the experiments. • Higher-order peaks are pointed out as signatures of presence of light at various location. • Predictions of this Letter shall be verified in future experiments. • The interpretation of the analyzed experiments shall be reviewed. - Abstract: By the means of the standard quantum mechanics formalism I present an explicit derivation of the structure of power spectra in Danan et al. and Zhou et al. experiments with nested dynamically changing Mach–Zehnder interferometers. The analysis confirms that we observe prominent, first-order peaks on frequencies related to some of the elements of the interferometer, but not on others. However, as I shall demonstrate, there are also other, weaker effects related to all relevant elements of the setup. In case of the Danan et al. setup, there are even peaks at all frequencies of element oscillations. When confronted in an experiment, these observations shall challenge the interpretation of the experiments based on anomalous trajectories of light.