Classical analog of quantum contextuality in spin-orbit laser modes

Abstract

We experimentally observed the violation of Kujula--Dzhafarov noncontextuality inequalities by nonseparable spin-orbit laser modes. Qubits are encoded on polarization and transverse modes of an intense laser beam. A spin-orbit nonseparable mode was produced by means of a radial polarization converter ($S$ plate). Our results show that the quantum contextuality can be emulated by nonseparable spin-orbit modes in an intense laser beam. Additionally, an improvement in the nonseparable 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.