Multi-path interferometry using single photons

In most experiments which search for violations of Born's rule using light the diffractive elements are formed from material slits, or waveguides, which are treated classically. In this article we propose an alternative approach where the internal energy levels of particles are used instead of slits to test the superposition principle, thus removing the effect of the finite width of the slits. By quantising both the light field and the diffraction elements we propose a new way to probe Born's rule for light in a fully quantum mechanical way.