Noncyclic continuous Pancharatnam—Berry phase in dual-beam interference

Abstract The geometric phase for classical electromagnetic light beams, in its original formulation as introduced by Pancharatnam, concerns fields experiencing cyclic, discrete in-phase polarization-state changes. A similar was later recognized Berry to govern the behavior of adiabatic quantum systems, with consequent extensions nonadiabatic and noncyclic evolutions state. However, no optical counterpart noncyclic, (continuous) evolution has been demonstrated. Here we employ a modified Young’s two-pinhole setup controlled pinhole polarizations intensities generate on interference an arbitrary continuous spatial polarization state, analogue case. customized arrangement allows separating at any point accumulated dynamical phases from total phase, enabling detailed study Pancharatnam–Berry transformation. Our theoretical experimental results are excellent agreement consistent geodesic rule evolutions.