Conical refraction: Experiments and large-scale demonstrations

Abstract

535.53.05Results of experiments on internal and external conical refraction on a rhombic sulfur single crystal are presented. A high-transmission optical scheme is suggested with light focusing on the crystal surface which allows two fringes of internal conical refraction ∼1 m in diameter to be observed in laser radiation. Two fringes of external conical refraction with unique polarization state are first observed, and conditions of light energy concentration along the biradial are discussed. The focusing power of a plane-parallel biaxial crystal plate is measured.

Free-space evolution of focused Gaussian beams transformed by conical diffraction in a biaxial crystal

“…With laser sources and available biaxial crystals, the effect of conical diffraction can easily be observed in simple optical arrangements [8,[10][11][12][13][14][15]. In one of such arrangements, the laser beam is focused close to the entrance surface of the crystal, so that the most focused image and a part of the conical diffraction pattern appear inside the crystal [8,10].…”

Conical diffraction complexified: dichroism and the transition to double refraction

“…In the pioneering observations [22][23][24], the incident beam profile was restricted by a pinhole, but the theory is considerably simplified by studying conical diffraction for Gaussian incident beams, for which the diffraction detail is different [5,8]. Moreover, Gaussian beams correspond to current experiments with lasers [9,[25][26][27]. Therefore we will develop the theory for Gaussian beams.…”

Conical refraction as a tool for polarization metrology

“…In CR [13][14][15][16][17][18][19][20][21], when a focused input Gaussian beam propagates along the optic axis of a biaxial crystal, it is transformed into a light ring, as shown in Fig. 1(a).…”