Wave-vector and polarization dependence of conical refraction

Abstract

We experimentally address the wave-vector and polarization dependence of the internal conical refraction phenomenon by demonstrating that an input light beam of elliptical transverse profile refracts into two beams after passing along one of the optic axes of a biaxial crystal, i.e. it exhibits double refraction instead of refracting conically. Such double refraction is investigated by the independent rotation of a linear polarizer and a cylindrical lens. Expressions to describe the position and the intensity pattern of the refracted beams are presented and applied to predict the intensity pattern for an axicon beam propagating along the optic axis of a biaxial crystal.

Conical refraction: fundamentals and applications

“…The state of polarization and the optical singularities generated with low values of ρ 0 will be addressed in Chapter 4. Finally, note that the methods presented in this Chapter could be extended to alternative input beams such as elliptical beams, which have been studied in detail in CR [54], to generate elliptical beams with transverse flat-top cross-section.…”

“…In CR, for ρ 0 ≫ 1, the SOP of the beam at the focal plane is already well known [54,59,74,131]. In this Chapter we investigate the CR SOP out of the focal plane, including values of ρ 0 1, when Poggendorff fine splitting vanishes.…”

“…2.17(a). Every point of the ring is a CR-filtered beam defined by the polar angle χ of the filtering (which also defines the plane of wave-vectors Φ K = χ [54]) and by the plane of its electric field vector with polarization azimuth Φ χ given by Eq. (2.44).…”

“…The biaxial crystal splits every plane wave into two new plane-waves. At the focal plane, these two plane-waves are refracted at positions on the ring characterized by their azimuthal angle ϕ = φ k and ϕ = φ k + π [54]. As a consequence, when one azimuthal sector of the Gaussian beam is blocked, the azimuthally opposite sector partially compensates the absence of the blocked sector.…”

“…On the other hand, Sokolovskii and co-workers showed that the Belsky-Khapalyuk-Berry equations can be re-arranged so that they describe CR in terms of the interference between two co-propagating cones [59], being this theory demonstrated experimentally and newly re-formulated by us [56], as it is shown in Section 2.4. Alternatively, we have also presented a novel proposal that can be used to easily predict the CR pattern at the focal plane by means of a wave-vector and polarization formalism [54] that can be also used in a cascade of biaxial crystals, as we have also shown in Ref. [55].…”