  We propose a measurement scheme to directly detect odd-frequency
superconductivity via time- and angle-resolved photoelectron fluctuation
spectroscopy. The scheme includes two consecutive, non-overlapping probe pulses
applied to a superconducting sample. The photoemitted electrons are collected
in a momentum-resolved fashion. Correlations between signals with opposite
momenta are analyzed. Remarkably, these correlations are directly proportional
to the absolute square of the time-ordered anomalous Green's function of the
superconductor. This setup allows for the direct detection of the "hidden order
parameter" of odd-frequency pairing. We illustrate this general scheme by
analyzing the signal for the prototypical case of a two-band superconductor.
