Hi, Roya I suggest you increasing the resolution to 100, dpml to 5, and I think your df may be too wide(df=4), maybe changing to 1 is better. That's my experience, hope it may help to you.
Regards, Lei Rao > Message: 2 > Date: Wed, 8 May 2013 01:38:23 -0700 (PDT) > From: ---- ---- <[email protected]> > To: "[email protected]" <[email protected]> > Subject: [Meep-discuss] MIM (metal-insulator-metal) dispersion > Message-ID: > <[email protected]> > Content-Type: text/plain; charset="iso-8859-1" > > > > Hello Everyone,? > > Does anyone know or have?experience?on calculating MIM dispersion with MEEP?? > > My code is as following however I do not get any reasonable graph. My > reference paper is: > > "Plasmon slot waveguides: Towards chip-scale propagation with > subwavelength-scale localization" > > The link for this paper is:? > http://prb.aps.org/abstract/PRB/v73/i3/e035407 > > > I intend to obtain the dispersion graph for Ag-Sio2-Ag structure, which is > given in the Figure2.b ?of the paper above. > I can obtain dispersion graph for lossy Drude metal, but not for > Lorentz-Drude metal. I have played with different parameters as much as I > could. > The only thing I am suspected is the location of PML layers and how to set > them. I tried many configuration but no satisfactory result! > > Any help or comment is appreciated.? > > Here is the code > *********************************************************************************************************************************** > (define-param a 100) > (set! resolution 50) > (define-param sy 4) ? ? ? ?;size of cell in Y direction > (define-param epsinf 1) > (define-param eps 2.37) ? ? ;dielectric function of Sio2 > (define-param w (/ 100 a)) ?; width of waveguide > (define-param fcen 0.15) ? ?;pulse center frequency ? ? ? ? ? ? ? ? ? ? ? ? ? > ? > (define-param df 4) ? ? ? ? ? ? ?;pulse width (in frequency)? > (define-param dpml 1) > > ;defines Lorentz-Drude metal normalized to a=100 nm? > > (define Silver (make dielectric (epsilon epsinf) > (polarizations > (make polarizability > (omega 1e-20) (gamma 0.0038715) (sigma 4.4625e+39)) > (make polarizability > (omega 0.065815) (gamma 0.31343) (sigma 7.9247)) > (make polarizability > (omega 0.36142) (gamma 0.036456) (sigma 0.50133)) > (make polarizability > (omega 0.66017) (gamma 0.0052426) (sigma 0.013329)) > (make polarizability > (omega 0.73259) (gamma 0.07388) (sigma 0.82655)) > (make polarizability > (omega 1.6365) (gamma 0.19511) (sigma 1.1133)) > ))) > > > (set! geometry-lattice (make lattice (size no-size (+ sy (* 2 dpml)) > no-size))) > (set! pml-layers (list (make pml (thickness dpml)(direction Y)))) > > (set! geometry (list > ? ? ? ? ? ? ? ? (make block (center 0 0) (size infinity sy infinity) > (material Silver)) > ? ? ? ? ? ? ? ? (make block (center 0 0) (size infinity w infinity) > ? ? ? ? ? ? ? ? (material (make dielectric (epsilon eps)))))) > > (set! sources (list > ? ? ? ? ? ? ? ?(make source > ? ? ? ? ? ? ? ? ?(src (make gaussian-src (frequency fcen) (fwidth df))) > ? ? ? ? ? ? ? ? ?(component Hz) (center 0.1 0.1)))) > > > (set! eps-averaging? false); disable sub-pixel averaging > > > ;Applies Bloch-periodic boundary conditions along x axis > > (define-param k-points? > (list? > (vector3 0 0 0) ? ? ;Gamma > ? ? ? ? (vector3 2.0 0 0) ? ;X > ? ? ? ? ) > ) ?? > > ; define a series of k-points > (define-param k-interp 20)? > (set! k-points (interpolate k-interp k-points)) > > ; calculates frequencies for these k-points > (run-k-points 300 k-points) > ? > ****************************************************************************************************************************************************************** > Thank you, > Roya > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://ab-initio.mit.edu/pipermail/meep-discuss/attachments/20130508/688231b3/attachment-0001.html> > > ------------------------------ > > _______________________________________________ > meep-discuss mailing list > [email protected] > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss > > End of meep-discuss Digest, Vol 87, Issue 6 > ******************************************* _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
