  Hong-Ou-Mandel interferometers are valuable tools in many Quantum Information
and Quantum Optics applications that require photon indistinguishability. The
theoretical limit for the Hong-Ou-Mandel visibility is 0.5 for
indistinguishable weak coherent photon states, but several device imperfections
may hinder achieving this value experimentally. In this work, we examine the
dependence of the interference visibility on various factors, including (i)
detector side imperfections due to after-pulses, (ii) mismatches in the
intensities and states of polarization of the input signals, and (iii) the
overall intensity of the input signals. We model all imperfections and show
that theoretical modeling is in good agreement with experimental results.
