We present a simple setup allowing undergraduate students to reproduce the Hong–Ou–Mandel experiment
during a half-day labwork session and observe the coalescence of two indistinguishable photons
merging on a balanced beamsplitter. This two-photon interference effect, fundamentally related to
the bosonic character of the photons, is commonly used in the fields of quantum communication and
computing to test the indistinguishability of two single-photon wavepackets. The setup makes use of
very few optical elements and requires little alignement that can be performed by students
themselves. It allows them to gather essential experimental skills related to parametric crystals,
fibre optics and single-photon detection, and to transpose abstract concepts of quantum physics to a
hands-on experiment in the lab.