We present a single-photon source based on the stimulated four-wave mixing process with
adjustable linear state of polarization. This source allowed us to generate non-orthogonal
states of polarization, that can be used for quantum key distribution experiments. The
average number of photon counts as a function of the angle of the analyzer was obtained
for two non-orthogonal linear states of polarization. The results show an accurate detection
after propagation through a standard single-mode optical fiber with a length equal to
20 km. We also employed a master/slave configuration between two avalanche photodiodes,
in order to check the probability of our single-photon source to emit pulses with
more than one photon, for an average number of photons per pulse, μ ∼ 0.2, and consequently
the probability of a photon to choose one of the paths. Results show that our
experimental scheme is suitable for polarization-encoding experiments.