Structure of the dielectric tensor in nematic liquid crystals with topological charge.
A q-plate is a stratified medium composed of a uniaxial nematic liquid crystal with an inhomogeneous orientation of the optical axis possessing a topological charge q, which looks promising as a switching device. This work reports an approach to diagonalizing the dielectric tensor in q-plates, giving a detailed study of nontrivial tensor coordinate transformations. The relationship between the diagonal dielectric tensor and the topological charge of the plate is established. From that, the dielectric tensor for a given q-plate can be explicitly calculated in a convenient frame, and hence the field propagation equations can be derived. These studies establish a theoretical basis that could further deepen the research on these particular structures for nonconventional manipulation of the light.
Vaveliuk
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Departamento de Optica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, Av. Complutense s/n, 28040 Madrid, Spain. pablov@fisica.ufpb.br
Moraes
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Fumeron
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Martinez Matos
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Calvo
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