Conversion of Arbitrary Three-Dimensional Polarization States to Regular States via Spin Cancellation

The present work is motivated by the necessity of handling and controlling three-dimensional polarization states, whose appropriate preparation has increasing interest in areas like nanotechnologies, quantum computing and near-field phenomena. By virtue of the so-called characteristic decomposition, any polarization state of light can be represented as an incoherent superposition of a pure state, a fully unpolarized state and a discriminating state. The discriminating component has nonzero spin in general, in which case the state is said to be nonregular. A simple procedure to transform an arbitrary nonregular state to a regular one through its incoherent composition with a pure state is described, resulting in a state that lacks a discriminating component. In addition, a method to suppress the spin vector of any given polarization state through its incoherent combination with a circularly polarized pure state is presented. Both approaches allow for the configuration of polarization states with simple features.