Phase singularities are locations where light is twisted like a corkscrew, with positive or negative topological charge depending on the twisting direction. Among the multitude of singularities arising in random wave fields, some can be found at the same location, but only when they exhibit opposite topological charge, which results in their mutual annihilation. New pairs can be created as well. With near-field experiments supported by theory and numerical simulations, we study the persistence and pairing statistics of phase singularities in random optical fields as a function of the excitation wavelength. We demonstrate how such entities can encrypt fundamental properties of the random fields in which they arise.

Phys. Rev. Lett.

De Angelis, L., Alpeggiani, F., Di Falco, A., & Kuipers, K. (2017). Persistence and lifelong fidelity of phase singularities in optical random waves. Phys.Rev.Lett., 119(20, Article number: 203903), 1–5. doi:10.1103/PhysRevLett.119.203903