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Topological defects caused by inhomogeneity of optical activity

Vasylkiv Yu., Skab I. and Vlokh R.

Vlokh Institute of Physical Optics, 23 Dragomanov Street, 79005 Lviv, Ukraine

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Abstract. The present work is devoted to analysis of the effect of inhomogeneous axial fields (torsion and bending mechanical stresses, as well as conically shaped electric fields) on the optical activity in crystals belonging to different point symmetry groups. It is found that the topological defects of gyration surface orientation with half-integer strengths can appear under the action of these fields. We discuss potentials of spiral phase plates made of optically active materials for generating vortex vector beams.

Keywords: topological defects, optical activity, inhomogeneity, torsion, bending, electric field, spiral phase plates, vector beams, optical vortices 

PACS: 78.20.Ek, 42.50.Tx, 78.20.hb, 78.20.Jq
UDC: 535.56
Ukr. J. Phys. Opt. 18 95-101
doi: 10.3116/16091833/18/2/95/2017
Received: 12.04.2016

Анотація. У роботі аналізовано вплив неоднорідних аксіальних полів (крутильних і згинаючих механічних напружень, а також конічного електричного поля) на оптичну активність кристалів, що належать до різних точкових груп симетрії. Виявлено, що під дією цих полів виникатимуть топологічні дефекти орієнтації гіраційної поверхні з напівцілим зарядом. Обговорено можливість використання спіральних фазових пластинок, виготовлених з оптично активних матеріалів, для формування вихрових векторних пучків. 
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