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Transmission and photonic band gaps in Fibonacci superlattices

Garus J., Garus S., Błoch K., Szota M., Nabiałek M., Szlązak K.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

229--235

EN

Purpose: The purpose of the article was to broaden the knowledge about the behavior of Fibonacci superlattices as filters electromagnetic waves. Design/methodology/approach: Simulations of multi-layer systems is usually carried out by using two complementary methods. The first, matrix method which allows the study of the properties of structures using transmission maps and the second method used is the Finite-Difference Time Domain (FDTD) algorithm allows on the study of electromagnetic wave propagation in the structure. Findings: It can be seen that the lighting of the filter with monochromatic light in the wavelength range of the band gap filter at the output causes propagation of low intensity in the range other than the wavelength of the incident beam. Research limitations/implications: The simulation was not considered the impact of losses in the material. Practical implications: Present clear differences depending on the polarization allow the use of superlattices as polarizers for specific ranges of wavelengths and angles of incidence. Originality/value: Fibonacci superlattices have been pre-tested in. The purpose of the article was to broaden the knowledge about the behavior of these structures as filters electromagnetic waves with a wavelength range from the near infrared, the effect of the material surrounding the transmission and increasing knowledge of the formation of band gaps.

2

The influence of extinction coefficient on transmission in binary multilayer

Garus S., Garus J., Szlązak K., Nabiałek M., Pietrusiewicz P., Błoch K., Gruszka K., Szota M.

Journal of Achievements in Materials and Manufacturing Engineering

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2013

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Vol. 61, nr 2

236--243

EN

Purpose: The influence of the extinction coefficient for transmission, reflectance and absorption in multilayer binary. Reps cluster was equal to 7 It was built of two types of materials. First was a NaCl equivalent with a refractive index described by nA=1.544-ik , and as second was GaAs lossless metamaterial equivalent Design/methodology/approach: Research was carried out using the map of: transmitting, reflectance and absorption of the electromagnetic wave. Maps determined using the matrix method. Findings: It is shown that the higher the extinction coefficient, which is responsible for the absorption of electromagnetic waves, decreases the transmittance and reflectance of the multilayer system at the same time increasing its absorption. Research limitations/implications: Would be a reasonable correlation between the results of the transmission, reflectance and absorption obtained using numerical methods with with experiment. Practical implications: Taking into account the extinction coefficient allows for a better representation of the real multilayer structures. Quasi one-dimensional superlattices can be used as filters or multiplexers electromagnetic waves. Originality/value: In the literature the most frequently analyzed lossless structure. Taking into account the extinction coefficient allows for better study the properties of the tested materials.

3

Badanie właściwości fazy skondensowanej metoda! Emisji niskoenergetycznych elektronów wspomagana analiza rentgenograficzna

Gągorowska B., Duś-Sitek M.

Inżynieria Powierzchni

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2006

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nr 2

87-91

PL

W pracy przedstawiono właściwości układów wielowarstwowych Cu/Ni wykorzystując metodę emisji niskoenergetycznych elektronów wspomaganą analizą rentgenograficzną. Otrzymane obrazy dyfrakcyjne dla układów przed nagrzewaniem wykazały obecność pików satelickich, z kolei dla próbek nagrzewanych do temperatury 933 K struktura ich została zachwiana. Z badań metoda emisji elektronów otrzymano krzywą emisyjną, na której obserwuje się dwa maksima. Nagrzewanie wymusza proces rozrostu obszarów nanokrystalicznych, tworzenia granic międzyfazowych oraz wystąpienie zjawisk transportowych. Aby uzyskać pełne informacje na temat emisji elektronów badano także stan powierzchni obydwu rodzajów próbek. Ponieważ zjawisko emisji elektronów wykorzystano jako metodę do kompleksowego badania faz krystalicznych, w pracy wykazano, że metodę tą można również wykorzystać do badania nanokrystalicznych struktur wielowarstwowych.

EN

The exoemission properties of multi-layered Cu/Ni systems are presented. Samples were tested using emission of low-energetistic electrons. Furthermore, the x-ray diffraction analysis was made to determine the quality of the multi-layer structure. The x-ray diffraction spectra for systems before heat treatment showed the presence of satellite peaks. Heating of samples up to 933 K induced some distortion of their structure. Investigation of electron emission resulted in determining the temperature dependence of the emission intensity, with characteristic two maxima peaks. Heat treatment of samples provokes the growth of nanocrystalline clusters, the formation of interfacial boundaries as well as pronouncement of transport phenomena. To obtain full information about emission of electrons, the surface topography of Cu/Ni superlattices was investigated. Until now electron emission phenomenon was used as a method of complex investigations of crystalline phase properties. The aim of this paper is to demonstrate, that the electron emission method is a valuable tool to investigate the nanocrystalline multi-layer structures.