  In single-particle entanglement (SPE) two degrees of freedom of a single
particle are entangled. SPE is a resource that can be exploited both in quantum
communication protocols and in experimental tests of noncontextuality based on
the Kochen-Specker theorem. SPE can be certified via a test of quantum
contextuality based on Bell inequalities. Experiments of Bell-like inequality
violation by single particle entangled systems may be affected by an analogue
of the locality loophole in this context, due to the presence of unavoidable
non-idealities in the experimental devices which actually produce unwanted
correlations between the two observables that are simultaneously measured. This
issue is tackled here by quantitatively analyzing the behaviour of realistic
devices in SPE experiments with photons. In particular, we show how it is
possible to provide a semi-device independent randomness certification of
realistic quantum random number generators based on Bell inequality violation
by SPE states of photons. The analysis is further enlarged to encompass, with a
Markovian model, memory effects due to dead time, dark counts and afterpulsing
affecting single photon detectors, in particular when not dealing with
coincidence measurements. An unbiased estimator is also proposed for quantum
transition probabilities out of the collection of experimental data.
