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Security sciences and their research areas

100%

Jakubczyk T.

nr 2(188)

47-60

The specificity of the 21st century filled with economic and social problems, acts of terror as well as armed conflicts downrightly necessitates undertaking the research in the field of security sciences. However, each time defining a subject of scientific research is of the utmost importance in order to systemize research works and mainly concretize interests. Such the aim was chosen by the author of the current article who, while presenting the orientations of individual scientific theoreticians and researchers dealing with security issues, answers the subject matter question: What does constitute the subject of the research in security sciences? The author’s inquiries were preceded by the explanation of the types of security and its scope within individual cases, which includes the essence of national and international security. In the further part of the article the author’s attention was focused on the sphere of methodology in security sciences. The author notices that the subject of research in the security science is of multidimensional character hence explanation, description, analyzing, assessing and forecasting the consequences of ongoing processes and events in the security sphere, together with initiation of activities which serve for ensuring security, require applying the knowledge from various scientific disciplines, domains and fields. In the following part of the article the attempt to define the subject of research in security sciences and drawing the conclusions within that field was undertaken. The author cites the orientations by A. Dawidczyk and T. Jemiolo according to whom the subject of research in security sciences is defined as the threat coming from human surroundings and all the activities aiming at ensuring and maintaining security for a man. The article is summarized by the conclusions where it was determined that in security sciences, the security, its components, ratio, level and relations with respect to the subject of research are studied.

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

32%

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

tom 116

nr 5

888-889

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.

MBE Growth and Characterization of a III-V Distributed Bragg Reflectors and InAs Quantum Dots

32%

Rousset J. , Słupinski T. , Jakubczyk T. , Kobak J. , Stawicki P. , Gołasa K. , Babinski A. , Nawrocki M. , Pacuski W.

nr 6

984-987

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.

Optical Properties of CdTe QDs Formed Using Zn Induced Reorganization

32%

Kobak J. , Pacuski W. , Jakubczyk T. , Kazimierczuk T. , Golnik A. , Frank K. , Rosenauer A. , Kruse C. , Hommel D. , Gaj J.

nr 5

627-629

In this paper we present optical studies of CdTe quantum dots formed using Zn-induced reorganization. The pattern of quantum dot photoluminescence lines is found to be similar to typical results reported for quantum dots grown with other techniques, although the positively charged exciton line is relatively more pronounced. Also the energy spacing between biexciton and exciton lines is found to be larger than in typical results. Zn-induced reorganization results in quantum dots density higher by an order of magnitude than in Te-induced quantum dots.