Effect of Polarization Mode Dispersion on Spontaneous Parametric Down Conversion Photon Pairs in Coincidence Counting

Hong-Ou-Mandel (HOM) interference is a cornerstone of many quantum information processing tasks. It relies on the destructive interference between Feynman paths and provides a measure of photon indistinguishability. For certain applications, e.g. in some quantum secure authentication schemes, the HOM readout needs to be performed remotely, i.e. far away from where the photons were originally created. It is therefore important to understand the effect of dispersion on the two-photon state and consequently its effect on the coincidence probability. Our work focuses on providing measurement data of the effect of polarization mode dispersion (PMD) on the HOM interference for photon pairs produced by spontaneous parametric down conversion (SPDC).