Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

6 Acta Physica Polonica A

Znaleziono wyników: 6

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Holographic Fabrication of Periodic Microstructures in Dichromated Pullulan

100%

Savić-Šević S. , Pantelić D. , Gajić R. , Isić G.

Acta Physica Polonica A

2007

tom 112

nr 5

1079-1082

Photonic crystal structures are fabricated in dichromated pullulan by the holographic technique. Relief structures of photonic lattices with rectangular, rhombic, and hexagonal arrays of peaks and holes are obtained. The structures have periodicities of the order 1.1μm and depth of about 50 nm.

Confined Metamaterial Structures Based on Coordinate Transformations

100%

Vasić B. , Gajić R. , Isić G. , Hingerl K.

Acta Physica Polonica A

2009

tom 116

nr 1

96-98

We apply transformation optics to structures in which the electromagnetic field is confined by highly conducting coatings. The possibility of changing the field propagation direction without perturbation is demonstrated on the example of a waveguide bend. Using this approach it is also possible to reshape a confined structure in order to meet certain external requirements and to redistribute a field in order to obtain desired field distribution. The structure implementation implies replacing a part of given confined structure with a metamaterial designed using the technique of transformation optics. Simplification of structure realization based on using reduced set of material parameters is examined. Our theoretical considerations are confirmed by full wave finite element simulations of a waveguide bend.

Imperfect Cloaking Devices Based on Metamaterials

88%

Isić G. , Gajić R. , Novaković B. , Popović Z. , Hingerl K.

Acta Physica Polonica A

2007

tom 112

nr 5

1083-1088

Cloaking devices designed using the coordinate transform approach were shown to be realizable, at least in principle, within the realm of electromagnetic metamaterials. In this paper we investigate the strictness of conditions imposed on the parameters of metamaterial cloaks by calculating the degree of wave scattering when those parameters have variations with respect to theoretically ideal values. A simple idea is used to obtain analytic results for the case of the nonideal two-dimensional cloaking cylinder. Also, results of realistic finite element simulations of the Helmholtz equation are presented and it is found that they are in excellent agreement with the analytic results.

Time Delay in Thin Slabs with Kerr-Type Nonlinearity

88%

Radovanović J. , Milanović V. , Isić G. , Ikonić Z. , Indjin D.

Acta Physica Polonica A

2007

tom 112

nr 5

987-992

In this paper we analyzed the following model: a thin slab with Kerr nonlinearity placed between two semi-infinite samples of linear and nonmagnetic materials. A general relation between the bidirectional group delay and the dwell time is derived for the thin slab. It is shown that the group delay is equal to the dwell time plus a self-interference delay. Particular attention is given to solving the Helmholtz equation for this case. Detailed and rigorous treatment revealed that the solutions of the Helmholtz equation are given via elliptic functions of the first kind. The boundary conditions at the interfaces are determined precisely. Finally, we provide an overall procedure for numerical calculation of the dwell times.

Spin Precession of Quasi-Bound States in Heterostructures with Spin-Orbit Interaction

75%

Isić G. , Indjin D. , Ikonić Z. , Milanović V. , Radovanović J. , Harrison P.

Acta Physica Polonica A

2009

tom 116

nr 4

513-515

We use a finite-difference model that is capable of describing the single state spin dynamics in a double-barrier AlGaAs heterostructure. The use of Green's functions enables a description of the double-barrier structure by a finite matrix while the interaction with contacts is described by appropriate self-energies. To account for interface roughness scattering, a self-energy Σp_{IR}(E, k) is derived within the random phase approximation. The dominant part is due to in-plane momentum relaxation while a smaller part describing spin-flip scattering is neglected. The former only decreases the state lifetime while the latter can also affect the spin precession frequency.

Modelling the Variable Angle Reflection and Transmission from Metamaterial Slabs

75%

Isić G. , Vasić B. , Mirić M. , Jokanović B. , Bergmair I. , Gajić R. , Hingerl K.

Acta Physica Polonica A

2009

tom 116

nr 4

631-634

We consider metamaterial slabs composed of perfectly conducting split-ring resonators. Assuming bianisotropic constitutive relations, we describe an S-parameter retrieval method that allows us to obtain the full material parameter tensors from numerically calculated S parameters. The retrieval has been done for various angles of incidence, ranging from 0° to 75°. It has been found that the parameters depend on the angle of incidence, but that this dependence is relatively small.