Singularity screening in generic optical fields

Opt Lett. 2015 Oct 15;40(20):4747-50. doi: 10.1364/OL.40.004747.

Abstract

We revisit the widely studied subject of screening in optical fields by topological charges and show that screening does not depend on charge ordering. Instead, for an array of N charges, screening requires that the variance of the charge fluctuations be small compared to N. We show by means of explicit examples that, when this requirement is met, screening can be complete, even for a spatially random arrangement of charges. We derive a minimal screening constraint on the charge correlation function and show that it is this constraint that is met in practice, rather than the more stringent constraints previously assumed.