On the dual-cone nature of the conical refraction phenomenon

TL;DR

This paper demonstrates a novel conical refraction pattern where a single bright ring forms without the typical Poggendorff splitting, achieved by using a specialized polarizer to select one of the two CR cones, aligning with the dual-cone model.

Contribution

It introduces a method to generate a single-ring CR pattern by selecting one cone, providing experimental support for the dual-cone model of conical refraction.

Findings

Single bright ring observed without Poggendorff splitting.

Polarizer enables control over the relative intensity of CR cones.

Absence of interference due to cone selection.

Abstract

In conical refraction (CR), a focused Gaussian input beam passing through a biaxial crystal and parallel to one of the optic axes is transformed into a pair of concentric bright rings split by a dark (Poggendorff) ring at the focal plane. Here, we show the generation of a CR transverse pattern that does not present the Poggendorff fine splitting at the focal plane, i.e. it forms a single light ring. This light ring is generated from a non-homogeneously polarized input light beam obtained by using a spatially inhomogeneous polarizer that mimics the characteristic CR polarization distribution. This polarizer allows modulating the relative intensity between the two CR light cones in accordance with the recently proposed dual--cone model of the CR phenomenon. We show that the absence of interfering rings at the focal plane is caused by the selection of one of the two CR cones.