Sökning: "artificial electromagnetic media"

Hittade 4 avhandlingar innehållade orden artificial electromagnetic media.

1. 1. Quantum Coherence and Quantum-Vacuum Effects in Some Artificial Electromagnetic Media

   Författare :Jianqi Shen; Sailing He; Chris Phillips; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Quantum coherence; quantum vacuum; electromagnetically induced transparency; negative refractive index; artificial electromagnetic media; electric- and magnetic-dipole transitions; multilevel atomic vapors; transient evolution; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Sammanfattning : The author of this thesis concentrates his attention on quantum optical properties of some artificial electromagnetic media, such as quantum coherent atomic vapors (various multilevel electromagnetically induced transparency vapors) and negative refractive index materials, and suggests some possible ways to manipulate wave propagations inside the artificial electromagnetic materials based on quantum coherence and quantum vacuum effects. In Chapters 1 and 2, the author reviews the previous papers on quantum coherence as well as the relevant work such as electromagnetically induced transparency (EIT), atomic population trapping and their various applications. LÄS MER

3. 2. Stealth radomes

   Författare :Sören Poulsen; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic scattering; Dichroic structures; Frequency selective surface; Elektroteknik; FSS; Electrical engineering; Radomes;

   Sammanfattning : This dissertation deals with periodic structures that are used as free-space electromagnetic filters. Two types of periodic structures are treated, namely the so called frequency selective surface (FSS) and the artificial puck plate (APP) structure. LÄS MER

4. 3. Numerical modelling of time-dependent metamaterials with the FDTD method

   Författare :Sergey Novozhilov; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; FDTD; time-dependent media; numerical modelling; computational electrodynamics; metamaterials;

   Sammanfattning : Metamaterials are artificial materials, usually composed of so-called meta-atoms, with electromagnetic properties which cannot be found in naturally occurring materials. In this work we study the properties of time-dependent metamaterials (meaning that their electromagnetic properties are varying with time), as well as their potential applications. LÄS MER

5. 4. Quantum Electro- and Acoustodynamics in Waveguides

   Författare :Andreas Josefsson Ask; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The study of light-matter interaction in superconducting quantum circuits has seen remarkable progress over the last $20$ years. By engineering artificial atoms, novel quantum phenomena have been demonstrated, and old ideas have come into a new light. LÄS MER