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open source FDTD solver with GPU support

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fdtd:materials [2018/02/01 14:06]
pklapetek
fdtd:materials [2018/02/01 14:19]
pklapetek
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 ==== Vacuum and linear materials ==== ==== Vacuum and linear materials ====
  
-These are handled using either lookup table or detailed arrays, however in both cases the material is defined by relative permittivity,​ permeability,​ electrical conductivity and magnetic conductivity,​ right as these appear in the Maxwell'​s equations. So, for vacuum this set would be (1 1 0 0).+These are handled using either lookup table or detailed arrays, however in both cases the material is defined by relative permittivity,​ permeability,​ electrical conductivity and magnetic conductivity,​ right as these appear in the Maxwell'​s equations. So, for vacuum this set would be (1 1 0 0). When handling such material within the basic geometric entities Gwyddion surfaces or tetrahedral mesh input, you can enter them with material type identifier 0 in order to get the four fields filled. If a lookup table approach is used, these materials should have material type identifier 1.
  
 ==== Ideal metals ==== ==== Ideal metals ====
 +
 +The only ideal metal model that we have now is a perfect electric conductor. This means that on the interface of such material the lateral electrical field components are zero. To enter such material, use tabulated values approach and set the material type identifier to 10.
  
 ==== Realistic metals ==== ==== Realistic metals ====
  
-There are the few different effects that we can observe when illuminating a nanoscale metallic structure. First of allwe can observe effect of spectral properties ​of the particular metal from which the structure is formedEven the simplest possible quantity observed on metals in everyday life - its excellent reflectivity - is material dependent and the different appearance ​of different ​metals ​is its consequenceThis can be handled via FDTD easily as there are many different algorithms enabling us to parametrize the spectral dependence of optical properties of metal and use them in the calculation. These algorithms also hide fact that the propagation of light through metal described only by its complex permittivity can’t be handled easily via conventional grid spacing and time steps. An example of calculated metal reflectivity via FDTD for different metals and algorithms is shown in section [[fdtd:​materials|Media]].+Special numerical models ​are usually used to treat the real metalsincluding them spectral properties ​within FDTDSuch approach ​is needed to handle properly ​the specific optical properties ​of metals. ​There are many different algorithms enabling us to parametrize the spectral dependence of optical properties of metal and use them in the calculation. These algorithms also hide fact that the propagation of light through metal described only by its complex permittivity can’t be handled easily via conventional grid spacing and time steps. ​ 
 + 
 + 
 +An example of calculated metal reflectivity via FDTD for different metals and algorithms is shown in section [[fdtd:​materials|Media]].
  
 {{ :​samples:​img_metals.png?​400 |}} {{ :​samples:​img_metals.png?​400 |}}
  
-Spectral ​dependences of metal surface reflectivity for different materials and different numerical techniques. Note that Chromium curves are almost entirely identical (so that ADE curve is hidden behind the RC one), and also Aluminum curves are very similar. For gold, slightly different dispersive properties were used for RC and for ADE/PLRC technique, using those presented in original papers, so the curves are not expected to be identical. Also, PLRC and ADE result for gold is indistinguishable.+The figure above shows spectral ​dependences of metal surface reflectivity for different materials and different numerical techniques. Note that Chromium curves are almost entirely identical (so that ADE curve is hidden behind the RC one), and also Aluminum curves are very similar. For gold, slightly different dispersive properties were used for RC and for ADE/PLRC technique, using those presented in original papers, so the curves are not expected to be identical. Also, PLRC and ADE result for gold is indistinguishable.
fdtd/materials.txt · Last modified: 2018/08/28 13:08 by pklapetek