The Experts below are selected from a list of 190158 Experts worldwide ranked by ideXlab platform
Jorg Evers - One of the best experts on this subject based on the ideXlab platform.
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ab initio quantum models for thin film x ray cavity qed
arXiv: Quantum Physics, 2020Co-Authors: Dominik Lentrodt, Kilian Peter Heeg, Christoph H Keitel, Jorg EversAbstract:We develop two ab initio quantum approaches to thin-film x-ray cavity quantum electrodynamics with spectrally narrow x-ray resonances, such as those provided by Mossbauer nuclei. The first method is based on a few-mode description of the cavity, and promotes and extends existing phenomenological few-mode models to an ab initio theory. The second approach uses analytically-known Green's functions to model the system. The two approaches not only enable one to ab initio derive the effective few-Level scheme representing the cavity and the nuclei in the low-excitation regime, but also provide a direct avenue for studies at higher excitation, involving non-linear or quantum phenomena. The ab initio character of our approaches further enables direct optimizations of the cavity structure and thus of the photonic environment of the nuclei, to tailor the effective quantum Optical Level scheme towards particular applications. To illustrate the power of the ab initio approaches, we extend the established quantum Optical modeling to resonant cavity layers of arbitrary thickness, which is essential to achieve quantitative agreement for cavities used in recent experiments. Further, we consider multi-layer cavities featuring electromagnetically induced transparency, derive their quantum Optical few-Level systems ab initio, and identify the origin of discrepancies in the modeling found previously using phenomenological approaches as arising from cavity field gradients across the resonant layers.
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x ray quantum optics with mossbauer nuclei embedded in thin film cavities
Physical Review A, 2013Co-Authors: Kilian Peter Heeg, Jorg EversAbstract:A promising platform for the emerging field of x-ray quantum optics consists of M\"ossbauer nuclei embedded in thin-film cavities probed by near-resonant x-ray light, as used in a number of recent experiments. Here we develop a quantum Optical framework for the description of experimentally relevant settings involving nuclei embedded in x-ray waveguides. We apply our formalism to two settings of current experimental interest based on the archetype M\"ossbauer isotope ${}^{57}$Fe. For the present experimental conditions, we derive compact analytical expressions and show that the alignment of medium magnetization, as well as incident and detection polarization, enable the engineering of advanced quantum Optical Level schemes. The model encompasses nonlinear and quantum effects which could become accessible in future experiments.
Tiejun Xia - One of the best experts on this subject based on the ideXlab platform.
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Extending software defined network principles to include Optical transport
IEEE Communications Magazine, 2013Co-Authors: S. Gringeri, Nabil Bitar, Tiejun XiaAbstract:Software defined networks are based on the principle of a centralized control plane separated from the network forwarding or switching plane that it controls. The switching plane can be heterogeneous, composed of network elements from multiple vendors, and it can provide distinct services with different characteristics, configurations, and control at the packet and/or Optical layers. Abstracting the control plane from the network elements allows network-platform-specific characteristics and differences that do not affect services to be hidden. In addition, software defined networking (SDN) is based on the principle that applications can request needed resources from the network via interfaces to the control plane. Through these interfaces, applications can dynamically request network resources or network information that may span disparate technologies. For instance, the application layer can dynamically request and obtain network resources at the packet flow, circuit, or even Optical Level based on application layer requirements. Current SDN implementations focus on Ethernet switching primarily for data center resource optimization. This article reviews the benefits and challenges of extending SDN concepts to various transport network architectures that include Optical wavelength and fiber switches, circuit switches, and sub-wavelength Optical burst switches. Control plane implementations for Optical networks are more complex since they must account for physical constraints including Optical signal reachability, bandwidth availability and granularity, light path routing, and light path reconfiguration speed. The long-term goal is to apply SDN concepts across multilayer multivendor networks in order to support a unified control structure.
Kilian Peter Heeg - One of the best experts on this subject based on the ideXlab platform.
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ab initio quantum models for thin film x ray cavity qed
arXiv: Quantum Physics, 2020Co-Authors: Dominik Lentrodt, Kilian Peter Heeg, Christoph H Keitel, Jorg EversAbstract:We develop two ab initio quantum approaches to thin-film x-ray cavity quantum electrodynamics with spectrally narrow x-ray resonances, such as those provided by Mossbauer nuclei. The first method is based on a few-mode description of the cavity, and promotes and extends existing phenomenological few-mode models to an ab initio theory. The second approach uses analytically-known Green's functions to model the system. The two approaches not only enable one to ab initio derive the effective few-Level scheme representing the cavity and the nuclei in the low-excitation regime, but also provide a direct avenue for studies at higher excitation, involving non-linear or quantum phenomena. The ab initio character of our approaches further enables direct optimizations of the cavity structure and thus of the photonic environment of the nuclei, to tailor the effective quantum Optical Level scheme towards particular applications. To illustrate the power of the ab initio approaches, we extend the established quantum Optical modeling to resonant cavity layers of arbitrary thickness, which is essential to achieve quantitative agreement for cavities used in recent experiments. Further, we consider multi-layer cavities featuring electromagnetically induced transparency, derive their quantum Optical few-Level systems ab initio, and identify the origin of discrepancies in the modeling found previously using phenomenological approaches as arising from cavity field gradients across the resonant layers.
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x ray quantum optics with mossbauer nuclei embedded in thin film cavities
Physical Review A, 2013Co-Authors: Kilian Peter Heeg, Jorg EversAbstract:A promising platform for the emerging field of x-ray quantum optics consists of M\"ossbauer nuclei embedded in thin-film cavities probed by near-resonant x-ray light, as used in a number of recent experiments. Here we develop a quantum Optical framework for the description of experimentally relevant settings involving nuclei embedded in x-ray waveguides. We apply our formalism to two settings of current experimental interest based on the archetype M\"ossbauer isotope ${}^{57}$Fe. For the present experimental conditions, we derive compact analytical expressions and show that the alignment of medium magnetization, as well as incident and detection polarization, enable the engineering of advanced quantum Optical Level schemes. The model encompasses nonlinear and quantum effects which could become accessible in future experiments.
Ákos Antal - One of the best experts on this subject based on the ideXlab platform.
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Bors Károly geodéziai műszertervező (1906-1975): Károly Bors, designer of surveying instruments (1906-1975) / Károly Bors, proiectant de instrumente de topografie (1906–1975)
Erdélyi Magyar Műszaki Tudományos Társaság – EMT Hungarian Technical Scientific Society of Transylvania Societatea Maghiară Tehnico-Ştiinţifică din Tr, 2020Co-Authors: Ákos AntalAbstract:Károly Bors one of the most well-known Hungarian designer of surveying instruments was born in Kunszetmiklós in 1906. He received his civil engineering degree at Royal Joseph University in 1933. With the recommendation of his professor Károly Oltay he began working at Hungarian Optical Works as a designer of surveying instruments. The importance and the modernity of his instruments was demonstrated by the fact that he was awarded the Kossuth Prize for designing successful and well-known instruments abroad in 1958. The instrument family – the Te-D1 theodolite, the Ni-B1 Optical Level and the Ma-1 plane table –, designed alongside his leadership, received the Grand Prix award at the World Exposition 1958 in Brussels. He received a scientific degree from the Hungarian Academy of Sciences for his activities in the field of design and scientific work in 1959. He taught at the Institute for Advanced Engineering of Technical University of Budapest for several years, lecture notes written by him on measuring technology are still in use Today. One of his greatest professional achievements was the introduction of the production of glass circles in Hungary. He died in 1975 in Budapest. The article presents the life and technical works of Károly Bors mainly from the point of view of evolution Hungarian surveying instruments industry. RezumatKároly Bors, unul dintre cei mai cunoscuți proiectanți maghiari de instrumente de topografie, s-a născut la Kunszetmiklós în 1906. A primit diploma de inginer civil la Universitatea Tehnică din Budapesta în 1933. Cu recomandarea profesorului său Károly Oltay, a început să lucreze la Magyar Optikai Művek (Compania Ungară de Optică) ca un proiectant de instrumente de topografie. Importanța și modernitatea instrumentelor sale a fost recunoscută și prin faptul că a primit Premiul Kossuth în 1958 pentru proiectarea și realizarea unor instrumente recunoscute și în străinătate. Familia instrumentelor proiectate sub conducerea lui – teodolitul Te-D1, dispozitivul de nivelare optic Ni-B1 și masa de măsurare Ma-1 – a primit Marele Premiu la Expoziția Mondială din 1958 de la Bruxelles. În 1959 a obținut diploma de candidat în științe tehnice de la Academia Maghiară. A predat la Institutul de Inginerie Avansată al Universității Tehnice din Budapesta, manualele scrise de el despre tehnologia de măsurare sunt folosite și astăzi. A murit la Budapesta în 1975. Articolul prezintă viața și lucrările tehnice ale lui Károly Bors în principal din punctul de vedere al evoluției industriei maghiare a instrumentelor de topografie. KivonatBors Károly, a legismertebb magyar geodéziai műszertervező 1906-ban született Kunszentmiklóson. A Királyi József Műegyetem szerzett kultúrmérnöki okLevelet 1933-ban. Professzora, Oltay Károly ajánlására került a Magyar Optikai Művekhez, ahol geodéziai műszerek tervezésével kezdett foglalkozni. Műszerei jelentőségét és korszerűségét bizonyítja, hogy 1958-ban több, a világpiacon is versenyképes korszerű műszer kidolgozásáért Kossuth-díjat kapott. Az 1958-as brüsszeli világkiállításon az irányítása mellett született és kiállított műszercsalád – a Te-D1 teodolit, az Ni-B1 szintező és az Ma-1 mérőasztal felszerelés – nagydíjat (Grand Prix) kapott. A Magyar Tudományos Akadémia Tudományos Minősítő Bizottsága 1959-ben addigi tudományos munkássága alapján a műszaki tudományok kandidátusává nyilvánította. Több éven keresztül tanított a Budapesti Műszaki Egyetem Mérnöktovábbképző Intézetében, az általa írt méréstechnológiai egyetemi jegyzetei azóta is használatban vannak. Az egyik legjelentősebb szakmai eredménye az üvegkörök gyártásának magyarországi bevezetése volt. 1975-ben halt meg Budapesten. Az alábbi tanulmány Bors Károly életét és műszaki alkotásait elsősorban a magyarországi geodéziai műszergyártás fejlődésének szemszögéből kívánja bemutatni.
S. Gringeri - One of the best experts on this subject based on the ideXlab platform.
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Extending software defined network principles to include Optical transport
IEEE Communications Magazine, 2013Co-Authors: S. Gringeri, Nabil Bitar, Tiejun XiaAbstract:Software defined networks are based on the principle of a centralized control plane separated from the network forwarding or switching plane that it controls. The switching plane can be heterogeneous, composed of network elements from multiple vendors, and it can provide distinct services with different characteristics, configurations, and control at the packet and/or Optical layers. Abstracting the control plane from the network elements allows network-platform-specific characteristics and differences that do not affect services to be hidden. In addition, software defined networking (SDN) is based on the principle that applications can request needed resources from the network via interfaces to the control plane. Through these interfaces, applications can dynamically request network resources or network information that may span disparate technologies. For instance, the application layer can dynamically request and obtain network resources at the packet flow, circuit, or even Optical Level based on application layer requirements. Current SDN implementations focus on Ethernet switching primarily for data center resource optimization. This article reviews the benefits and challenges of extending SDN concepts to various transport network architectures that include Optical wavelength and fiber switches, circuit switches, and sub-wavelength Optical burst switches. Control plane implementations for Optical networks are more complex since they must account for physical constraints including Optical signal reachability, bandwidth availability and granularity, light path routing, and light path reconfiguration speed. The long-term goal is to apply SDN concepts across multilayer multivendor networks in order to support a unified control structure.