Optical device for the precision control of the electric field in the focus of a beam

TL;DR

This paper introduces an inline optical device with four components that can generate and precisely control the electric field orientation in a laser beam focus, enabling continuous polarization variation.

Contribution

The novel optical device allows continuous and precise control of the electric field orientation in laser focus by rotating optical components, with estimated high angular resolution.

Findings

Device produces radially and linearly polarized sub-beams

Electric field orientation can be continuously varied in focus

Angular resolution estimates provided

Abstract

We present an inline optical device consisting of four optical components that produce a laser field consisting of two sub-beams where one is radially polarized and the other is linearly polarized. In the focus, the radially polarized sub-beam produces longitudinal polarization while the linearly polarized sub-beam produces polarization perpendicular to the propagation direction. By rotating the optical components, the orientation of the resulting electric field in the focus can be continuously varied in any direction. Estimates of the angular resolution of the device are given in the paraxial approximation.