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fdtd:sources [2018/01/29 17:22] pklapetek |
fdtd:sources [2018/08/28 15:18] (current) pklapetek [Sources] |
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- | To get focused source we can use plane waves summation method. | + | To get a focused source we can use plane waves summation method as published in Ref. [1]. This is based on decomposition of the ideal focused beam onto a set of plane wave with appropriate angles and phases. |
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- | Layered source | + | Layered source is a special source conditions suitable for materials with infinitely extending layers (e.g. thin films) as published in Ref. [2]. In our implementation the layers have to be laterally oriented in xy direction, so they have normal in z direction. The material can be formed by N layers in z-direction (in present implementation only dielectric and non-absorbing). Incident wave however can cross the sample at angle as well. |
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+ | {{ :samples:ltsf.png?600 |}} | ||
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- | Layered focused source | + | Layered focused source is a mixture of focused source plane wave summation and use of infinite layers in z direction, i.e. the above two sources. |
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+ | Finally, some of the sources can be also altered after they are set, e.g. to change the source profile. | ||
+ | This is the case of LTSF and TSF (in z direction) where we can multiply the plane wave entering the computational domain by a Gaussian to get a slightly diverging Gaussian beam. | ||
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+ | {{ :samples:img_source_gaussian.png?100|}} | ||
+ | Sample parameter file: {{samples:source_gaussian.tar.gz|TSF Gaussian source}}. | ||
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+ | A 250x180x200 computational domain with total/scattered field source, incidient at angle and multiplied by a Gaussian function. | ||
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+ | ==== Reference ==== | ||
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+ | [1] I.R.Capoglu, A. Taflowe, V. Backman, Optics Express 23 (2008) 19208. | ||
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+ | [2] I.R. Capoglu, G.S. Smith: IEEE Transactions on Antennas and Propagation 02/2008, 56:1. | ||
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