Simple model of the density of states in 1D photonic crystal

In this paper, we present a simple, yet versatile, analytical model of one-dimensional photonic crystal (1D PC). In our theoretical model, we take into account direction of propagation and therefore do not neglect anisotropic nature of photonic crystals. We derive analytical expressions for mode spectrum and density of states in 1D photonic crystal. With those formulas, we obtain mode spectrum characteristics, which depict formation of photonic band gap and reveal properties of photonic crystals.Comment: presented at SPIE International Congress on Optics and Optoelectronics, Warszawa, Poland, 28.08-2.09.200

Analysis of post-blasting source mechanisms of mining-induced seismic events in Rudna copper mine, Poland

The exploitation of georesources by underground mining can be responsible for seismic activity in areas considered aseismic. Since strong seismic events are connected with rockburst hazard, it is a continuous requirement to reduce seismic risk. One of the most effective methods to do so is blasting in potentially hazardous mining panels. In this way, small to moderate tremors are provoked and stress accumulation is substantially reduced. In this paper we present an analysis of post-blasting events using Full Moment Tensor (MT) inversion at the Rudna mine, Poland, underground seismic network. In addition, we describe the problems we faced when analyzing seismic signals. Our studies show that focal mechanisms for events that occurred after blasts exhibit common features in the MT solution. The strong isotropic and small Double Couple (DC) component of the MT, indicate that these events were provoked by detonations. On the other hand, post-blasting MT is considerably different than the MT obtained for strong mining events. We believe that seismological analysis of provoked and unprovoked events can be a very useful tool in confirming the effectiveness of blasting in seismic hazard reduction in mining areas

Orthonormal bases of extreme spin coherence

Spin anticoherent states acquired recently a lot of attention as the most "quantum" states. Some coherent and anticoherent spin states are known as optimal quantum rotosensors. In this work we introduce a measure of spin coherence for orthonormal bases, determined by the average anticoherence of individual vectors, and identify the most and the least coherent bases which lead to orthogonal measurements of extreme coherence. Their symmetries can be revealed using the Majorana stellar representation, which provides an intuitive geometrical representation of a pure state by points on a sphere. Results obtained lead to maximally (minimally) entangled bases in the $2j+1$ dimensional symmetric subspace of the $2^{2j}$ dimensional space of quantum states of multipartite systems composed of $2j$ qubits.Comment: 13 pages, 10 figure

Normalized Gaussian Approach to Statistical Modeling of OFDM Signals, Journal of Telecommunications and Information Technology, 2014, nr 1

This article concerns modeling of statistical properties of OFDM signals with the help of “normalized Gaussian” model, proposed by Kotzer et al. In this paper there is provided an extended formulation of the model, supplemented by an expression for probability density, extending possible applications of the model in theoretical works. Numerical results for verification of the model are provided and a more accurate alternative is suggested

Prawdopodobieństwo przejścia i efektywna liczba próbek cyfrowego sygnału z multipleksacją OFDM. Telekomunikacja i Techniki Informacyjne, 2012, nr 1-2

W artykule przedstawiono wyprowadzenie wyrażenia opisującego efektywną liczbę próbek sygnału cyfrowego z multipleksacją OFDM. Wyprowadzenie oparte jest na obliczeniu prawdopodobieństwa przejścia dla tego sygnału. Otrzymane wyrażenie wskazuje wprost zależności między efektywną liczbą próbek a parametrami sygnału i stanowi uzupełnienie modelu teoretycznego

Wymagania na rozdzielczość i nieliniowość przetwornika C/A dla sygnału OFDM. Telekomunikacja i Techniki Informacyjne, 2010, nr 3-4

Przedstawiono model analityczny, umożliwiający wyznaczenie błędów wnoszonych do sygnału OFDM w procesie przetwarzania cyfrowo-analogowego. Zaproponowano wyrażenia do oszacowania wymaganej rozdzielczości i dopuszczalnych nieliniowości przetwornika C/A, gwarantujących utrzymanie zniekształceń sygnału poniżej założonego poziomu

Calculation of atomic spontaneous emission rate in 1D finite photonic crystal with defects

We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.Comment: Cent. Eur. J. Phys, in pres

Orthonormal bases of extreme quantumness

Spin anticoherent states acquired recently a lot of attention as the most "quantum" states. Some coherent and anticoherent spin states are known as optimal quantum rotosensors. In this work, we introduce a measure of quantumness for orthonormal bases of spin states, determined by the average anticoherence of individual vectors and the Wehrl entropy. In this way, we identify the most coherent and most quantum states, which lead to orthogonal measurements of extreme quantumness. Their symmetries can be revealed using the Majorana stellar representation, which provides an intuitive geometrical representation of a pure state by points on a sphere. Results obtained lead to maximally (minimally) entangled bases in the $2j+1$ dimensional symmetric subspace of the $2^{2j}$ dimensional space of states of multipartite systems composed of $2j$ qubits. Some bases found are iso-coherent as they consist of all states of the same degree of spin-coherence

Relativistic, QED, and nuclear mass effects in the magnetic shielding of 3^3He

The magnetic shielding $\sigma$ of $^3$He is studied. The complete relativistic corrections of order $O(\alpha^2)$, leading QED corrections of order $O(\alpha^3 \ln\alpha)$, and finite nuclear mass effects of order $O(m/m_{\rm N})$ are calculated with high numerical precision. The resulting theoretical predictions for $\sigma = 59.967~43(10)\cdot 10^{-6}$ are the most accurate to date among all elements and support the use of $^3$He as a NMR standard.Comment: 10 pages, corrected minor errors in Eqs.(6,7