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  1. 25 Acta Physica Polonica A

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  1. 3 Jakubczyk T.

  2. 3 Pacuski W.

  3. 2 Golnik A.

  4. 2 Hocini A.

  5. 2 Hommel D.

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1
Content available remote

Optical Study of ZnTe-Based 2D and 0D Photonic Structures Containing CdTe/ZnTe Quantum Dots

100%
Jakubczyk T., Kazimierczuk T., Golnik A., Bienias P., Pacuski W., Kruse C., Hommel D., Kłopotowski Ł., Wojtowicz T., Gaj J.
Acta Physica Polonica A
|
2009
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vol. 116
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issue 5
888-889
EN
We report on an optical study of ZnTe-based microcavity and micropillars. Angle-resolved reflectivity studies confirm a high quality of the investigated structure by setting the lower bound on the quality factor Q ≥ 1000, determined from normal-incidence reflection spectra. In a microphotoluminescence study, micropillar modes are observed at temperatures of the order of tens of kelvins. For structures grown by a complex growth procedure at two different MBE facilities, an enhancement of photoluminescence in the cavity mode is observed.
2
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Near-Infrared Tunable Reflection and Absorption Using Nanostructured Thin Film Structures Employing Phase-Change Material

100%
Ozdemir A., Kocer H.
Acta Physica Polonica A
|
2016
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vol. 129
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issue 4
464-467
EN
We present the design of a polarization-dependent tunable nanostructured thin film absorber in the near-infrared region. Germanium antimonide tellurite (GST) was employed as the phase change material in the designed structure. Our structure is composed of a periodic grating-type array of 150 nm thick Au buried with 50 nm thick GST layer from the top of the Au layer. The period of the gratings is 2 µm and in each period, GST width is 1 µm. GST was selected as the active phase change material because its optical properties undergo a substantial change during a structural transition from amorphous to crystalline phase. The optical absorption and reflection properties of the designed structure with respect to the geometric and material parameters were systematically investigated using the finite difference time domain computations. It was shown that absorption peak or reflection dip at the resonant wavelengths in the near-infrared region was red shifted from 2039 nm to 2143 nm wavelength by switching the phase change material from its amorphous to crystalline states. The distributions of the electric field and absorbed power at the resonant wavelengths with respect to different phases of the GST were investigated to further explain the physical origin of the absorption. Our study provides a path toward the realization of tunable infrared absorbers for applications, such as selective infrared emitters, infrared camouflage, sensors, and photovoltaic devices.
3
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A Zero-Index Metamaterial Single Layer Superstrate for Patch Antenna Gain Enhancement

63%
Saleh C., Bensafieddine D., Laamari E., Bouzouad M.
Acta Physica Polonica A
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2015
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vol. 128
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issue 2B
B-307-B-309
EN
The objective of this paper is to use a zero refractive index n metamaterial as single layer superstrate suspended above a microstrip patch antenna (MPA), operating at 43 GHz, for the gain enhancement. The single metamaterial layer superstrate is composed of a periodic arrangement of Jerusalem cross unit-cells, and behaves as an homogeneous medium characterized by a refractive index close to zero. This metamaterial low index property allows gathering radiated waves from the antenna and collimates them towards the superstrate normal direction. The proposed design improves the antenna gain by 5.1 dB.
4
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New Type of Composite Gyrotropic Metamaterial

51%
Paśko W., Zięba P., Tralle I., Çoruh A.
Acta Physica Polonica A
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2017
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vol. 132
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issue 1
121-123
EN
In this work we examined the possibility of fabricating the metamaterial in a relatively simple way. Our idea was to use the three-component mixture of ingredients, where one of them is responsible for the negative permeability μ(ω) of hypothetical metamaterial, while the other two cause the negative value of effective permittivity ε(ω). In our previous work, we considered Hg_{1-x}Cd_xTe semiconductor compound as one of the ingredients of mixture. As fabrication of the Hg_{1-x}Cd_xTe is related to using mercury which is very poisoning, we tried to exclude this material. In the work we proved by numerical simulations the possibility of substituting mercury cadmium telluride by Pb_{1-x}Sn_xTe. We have shown by computer simulations that by the proper fitting of the parameters, e.g. the radius of nanoparticles, their magnetic moments, the relative concentration of ingredients, etc., it is possible to obtain the metamaterial with negative refraction index in a relatively broad range of temperatures and magnetic fields. The last seems to be very promising in terms of practical applications of metamaterials.
5
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Planar Photonic Crystals Biosensor Applications of TiO_2

51%
Erdiven U., Karaaslan M., Unal E., Karadağ F.
Acta Physica Polonica A
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2012
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vol. 122
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issue 4
732-736
EN
We examine quality factor and sensitivity change depending on the resonant wavelength changing refractive index of surrounding liquid for TiO_2 photonic crystal slab structure. Photonic crystal slab structure is used widely for biological materials such as proteins, antigens, DNA, cells, virus particles and bacteria. Mentioned photonic crystal slabs are usable with large-area biosensor designs. They permit direct access to externally incident optical beams in a microfluidic device. Model calculations are based on two-dimensional periodic crystal structure. Photonic crystal slab consists of a square lattice of air holes in a finite-thickness dielectric slab. The time domain simulations were implemented by software MIT Electromagnetic Equation Propagation.
6
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Structural and Optical Properties of Alternately-Strained ZnS_{x}Se_{1-x}/CdSe Superlattices with Effective Band-Gap 2.5-2.6 eV

51%
Evropeytsev E., Sorokin S., Gronin S., Sedova I., Klimko G., Sitnikova A., Baidakova M., Ivanov S., Toropov A.
Acta Physica Polonica A
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2014
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vol. 126
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issue 5
1156-1158
EN
We report on design and fabrication of alternately-strained ZnS_xSe_{1-x}/CdSe short period superlattices with the effective band-gap 2.52, 2.58, and 2.61 eV and the total thickness ≈300 nm. Transmission electron microscopy, X-ray diffraction, and photoluminescence measurements reveal negligibly small density of misfit dislocations in the superlattices. The investigation of carrier transport along the superlattice growth axis, performed by the photoluminescence measurements of a superlattice with one enlarged quantum well, confirms efficient Bloch-type transport at temperatures above ≈ 100 K. Such superlattices look promising for the applications as a material for the wide band-gap photoactive region of a multi-junction solar cell comprising both III-V and II-VI materials.
7
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GaAs-Based Quantum Well Exciton-Polaritons beyond 1 μm

51%
Pieczarka M., Podemski P., Musiał A., Ryczko K., Sęk G., Misiewicz J., Langer F., Höfling S., Kamp M., Forchel A.
Acta Physica Polonica A
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2013
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vol. 124
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issue 5
817-820
EN
Realization of the Bose-Einstein condensate can provide a way for creation of an inversion-free coherent light emitter with ultra-low threshold power. The currently considered solutions provide polaritonic emitters in a spectral range far below 1 μm limiting their application potential. Hereby, we present optical studies of InGaAs/GaAs based quantum well in a cavity structure exhibiting polaritonic eigenmodes from 5 to 160 K at a record wavelength exceeding 1 μm. The obtained Rabi splitting of 7 meV was almost constant with temperature, and the resulting coupling constant is close to the calculated QW exciton binding energy. This indicates the very strong coupling conditions explaining the observation of polaritons at temperatures where the exciton dissociation is already expected, and allows predicting that room temperature polaritons could still be formed in this kind of a system.
8
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Epitaxial Growth and Optical Properties of PbTe/CdTe Semiconductor Heterostructures

51%
Szot M., Kowalczyk L., Smajek E., Domukhovski V., Domagała J., Łusakowska E., Taliashvili B., Dziawa P., Knoff W., Wiater M., Wojtowicz T., Story T.
Acta Physica Polonica A
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2008
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vol. 114
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issue 5
1391-1396
EN
Growth optimization, optical and structural properties of PbTe/CdTe multilayers grown by molecular beam epitaxy on GaAs (001) as well as on BaF_2 (111) substrates is reported. An intense photoluminescence in the mid-infrared region is observed from PbTe quantum wells excited with 1.17 eV pulsed YAG:Nd laser. The energy of the emission peak shows blue shift with decreasing PbTe well width and has a positive temperature coefficient. The influence of thermal annealing on photoluminescence spectra of PbTe/CdTe multilayers grown on BaF_2 substrate is discussed.
9
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Plasmonic Bragg Reflector and Tamm Plasmon Polaritons in Metal-Dielectric Superlattices

51%
Vukovic S.
Acta Physica Polonica A
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2009
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vol. 116
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issue 4
678-680
EN
The properties of electromagnetic waves in two-dimensional periodic structures created by alternating metal and dielectric layers are investigated. The structure is assumed to be finite in the direction normal to the layers and infinite in other directions. Dispersion relations for both TE- and TM-polarized eigenmodes of metal-dielectric superlattice have been analyzed. It is demonstrated that the dispersion show typical properties of optic Tamm states.
10
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Enhancement of Refractive Index Sensitivity in Photonic Crystal Waveguide-Based Sensors by Selective Infiltration

51%
Bagci F., Akaoglu B.
Acta Physica Polonica A
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2013
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vol. 124
|
issue 1
50-55
EN
We present a liquid refractive index sensor based on a photonic crystal waveguide slab structure. Sensing mechanism employed in this study is based on the shift in cut-off wavelength as the lattice holes are selectively infiltrated. Three-dimensional plane-wave expansion and finite-difference time-domain methods are used to determine the band structure and transmission spectra, respectively. First, the sensitivity of the device is analyzed for the structure where only the first rows of holes adjacent to the line-defect are infiltrated. In addition, this analysis is repeated for a range of hole diameters. Second, the effects of infiltrated holes which are placed in the line-defect are investigated. As these infiltrated central holes are introduced, the proposed device exhibits 5.3 times improved sensitivity.
11
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Electronic States in Type-II Superlattices

51%
Machowska-Podsiadlo E., Bugajski M.
Acta Physica Polonica A
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2009
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vol. 116
|
issue S
S-65-S-68
EN
In this paper the electronic states in type-II superlattices are demonstrated. Band dispersions of InAs/GaSb periodic structure were calculated with the respect of the light and the heavy holes states mixing at InAs/GaSb interfaces. The effect of narrow energy band gap of InAs was taken into account and the wavelengths corresponding to optical transitions in the superlattice were presented.
12
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Toward Better Light-Confinement in Micropillar Cavities

51%
Ściesiek M., Gietka K., Golnik A., Kossacki P., Jakubczyk T., Pacuski W., Kruse C., Hommel D.
Acta Physica Polonica A
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2011
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vol. 120
|
issue 5
877-879
EN
We report on a two-step etching of ZnTe based micropillars. We demonstrate applicability of the technology and we analyze the optical properties of obtained structures. Microphotoluminescence spectra of individual micropillars show a typical mode pattern that confirms a successful growth of photonic structures. The reflectivity and photoluminescence spectra of a planar microcavity measured for various incident angles show that additional side distributed Bragg reflectors will be important for the further enhancement of photon confinement in micropillar cavity.
13
Content available remote

Effect of Nonlinear Elasticity on Interband and Intersubband Transition Energies in GaN/AlN Superlattices

51%
Łepkowski S.
Acta Physica Polonica A
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2007
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vol. 112
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issue 2
315-319
EN
We present a theoretical study of the effect of nonlinear elasticity on interband and intersubband transition energies in wurtzite GaN/AlN superlattices. The effect of nonlinear elasticity is considered by taking into account the changes of elastic constants caused by the intrinsic hydrostatic pressure, originating from lattice misfit between constituents of the superlattice. We show that the influence of the effect of the nonlinear elasticity on the interband and intersubband transition energies in the GaN/AlN superlattices depends crucially on the strain state of structures, in particular on the in-plane lattice constant of the buffer or the substrate. For the superlattices strained to AlGaN buffers with small aluminum concentrations, the effect of nonlinear elasticity increases significantly the interband transition energy and decreases the intersubband transition energy. For the superlattices strained to AlGaN buffers with large aluminum concentrations, the effect of nonlinear elasticity leads to a decrease in the interband transition energy and an increase in the intersubband transition energy.
14
Content available remote

Design of Pressure Sensor Based on Two-Dimensional Photonic Crystal

51%
Zouache T., Hocini A., Harhouz A., Mokhtari R.
Acta Physica Polonica A
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2017
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vol. 131
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issue 1
68-70
EN
In this work, we design a new pressure sensor based on two-dimensional photonic crystal waveguide coupled to a point-defect resonant microcavity. The mechanism of sensing is based on the change of the germanium refractive index as function of the hydrostatic pressure P. The resonant wavelength will shift when pressure variation induces change in the refractive indexes of the structure. The pressure variation causes the shifting of defect modes. The properties of the refractive index sensor are simulated using the finite-difference time-domain algorithm and the plane wave expansion method. These kinds of sensors have many advantages in compactness, high sensitivity, and various choices of materials.
15
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Effect of HRT ZnO Film on Optical Spectra of Transmission in CdS/CdTe Solar Elements

51%
Danylov A., Ilchuk H., Petrus R.
Acta Physica Polonica A
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2018
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vol. 133
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issue 4
981-983
EN
The comprehensive analysis of transmission spectra for light propagated through ITO/ZnO/CdS multilayers to solar cell active layer of CdTe is performed. Optimal thickness of ZnO high resistive oxide supplying minimal optical losses in CdTe solar cell working range was determined. We get the maximal light transmission to active layer for ZnO film with thickness of 230 nm. The advantages of glass superstrate for multilayer structure with ZnO upper layer is discussed in comparison with the structure with ITO upper layer. Calculation of transmittance for textured surfaces of top face of solar element showed significant minimization of optical losses in the structure with ITO upper layer textured by inverted pyramids while for textured glass superstrate there is no ponderable profit as compared to multilayer structure with planar surface.
16
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Quantization of Electromagnetic Modes in a Hyperbolic Negative-Index Layered Superconductor Slab

51%
Cortés-López S., Pérez-Rodríguez F.
Acta Physica Polonica A
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2016
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vol. 130
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issue 2
641-644
EN
We theoretically study the infrared reflectivity and transmissivity of a high-temperature layered superconductor slab. Both infrared spectra exhibit very narrow Fabry-Perot resonances associated with the quantization of the wave vector of the TM electromagnetic modes. The resonances are observed in a pass band where the refractive index of the layered superconductor is negative. The pass band of negative dispersion is above the Josephson plasma frequency which appears in the expression for the effective permittivity component, corresponding to the direction perpendicular to the layers. It was found that the Fabry-Perot resonances undergo a blue shift as the slab thickness or the angle of incidence are increased. Moreover, the quantized electromagnetic modes turn out to be quasi-longitudinal because of the strong anisotropy of the infrared dielectric response of the layered superconductor.
17
Content available remote

Excitonic Polaritons in Semiconductor Micropillars

51%
Bajoni D., Wertz E., Senellart P., Miard A., Semenova E., Lemaître A., Sagnes I., Bouchoule S., Bloch J.
Acta Physica Polonica A
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2008
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vol. 114
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issue 5
933-943
EN
We describe the physics of cavity polaritons in semiconductor micropillars. Cavity polaritons are exciton-photon entangled states arising from the strong coupling between excitons and the optical modes of a cavity. In micropillars, the photon three-dimensional confinement results in a discrete spectrum of 0D polariton states. Characterization of the linear properties of these micropillars will be presented. Then we will show how this system can be used to generate parametric photons and to obtain polariton lasing.
18
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MBE Growth and Characterization of a III-V Distributed Bragg Reflectors and InAs Quantum Dots

51%
Rousset J., Słupinski T., Jakubczyk T., Kobak J., Stawicki P., Gołasa K., Babinski A., Nawrocki M., Pacuski W.
Acta Physica Polonica A
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2012
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vol. 122
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issue 6
984-987
EN
We describe the realization and characterization of a distributed Bragg reflectors and InAs quantum dots grown by molecular beam epitaxy. The distributed Bragg reflectors are based on a stack of eight or twenty pairs of GaAs and AlAs layers with a stopband centered at about E_0=1.24 eV (λ_0=1000 nm). The whole structures exhibit a reflectivity coefficient above 90%. The growth rate was monitored in situ by measurement of the oscillations of the thermal emission intensity. The investigations conducted on the InAs quantum dots grown on GaAs show photoluminescence around E=1.25 eV (λ=990 nm). The combination of these two elements results in the realization of a microcavity containing InAs quantum dots and surrounded by 20 pairs of distributed Bragg reflectors.
19
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Optical Properties of SbSI Photonic Crystals

51%
Kępińska M., Starczewska A., Duka P., Nowak M., Szperlich P.
Acta Physica Polonica A
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2014
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vol. 126
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issue 5
1115-1117
EN
This paper presents optical properties of SiO_2 opals infiltrated with SbSI and inverted SbSI opals for the first time. Registered reflectance spectra exhibit Bragg's peaks connected with photonic band gap. Calculated photonic band structure has been compared with experimental results.
20
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A Study of Chirality in Gold Nanostructures with Second Harmonic Generation

51%
Valev V., Silhanek A., Gillijns W., Moshchalkov V., Verbiest T.
Acta Physica Polonica A
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2009
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vol. 116
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issue 4
498-500
EN
We present the second harmonic generation - circular dichroism response from G-shaped gold nanostructures for P-polarized incoming light. By eliminating the contributions of anisotropy to the signal, an absolute measure of the second harmonic generation - circular dichroism is presented. The system of planar nanostructures is an excellent model for studying the correlation between optical properties and chiral morphology at the nanoscale. Samples with both enantiomorphs of the chiral pattern were prepared and, demonstrating the unambiguous presence of chirality, the second harmonic generation - circular dichroism response from two such samples was fitted simultaneously with a single set of fitting parameters.
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