  We experimentally observed the violation of Kujula-Dzhafarov noncontextuality
inequalities by non-separable spin-orbit laser modes. Qubits are encoded on
polarization and transverse modes of an intense laser beam. A spin-orbit
non-separable mode was produced by means of a radial polarization converter
(S-plate). The results show that contextuality can be investigated by using
spin-orbit modes in a simple way, corroborating recent works stating that such
system can emulate single-photon experiments. Additionally, an improvement in
the non-separable mode preparation allowed us to observe a greater violation of
the Clauser-Horne-Shimony-Holt inequality for such system. The results are in
very good agreement with the theoretical predictions of quantum mechanics.
