hello, Matt I have already disable this basic averaging, and the results I got still have some other averaging. Liang Huo
在2007-11-05，matt <[EMAIL PROTECTED]> 写道： Hello, Meep still does some averaging, even when you set eps-averaging? to false. There's a description of how to disable this averaging here: http://article.gmane.org/gmane.comp.science.electromagnetism.meep.general/726 Best, Matt On Sun, 4 Nov 2007, huoliangcl2 wrote: > Dear Steven and meep users, > I have been using meep to simulate spp of gold+dielectric structure for > a while, but the simulated result cann't conform to the analytical > result,the meep calculated dispersion curve of spp is lower than > the curve calculated by the equation ksp=k0*sqrt(epsm*epsd/epsm+epsd) . > If I increase the resolution the simulated result get closer to the > analytical result, see the attached figure, but I think the resolution does > not necessarily to be so high to get the correct result. > I think perhaps it's the problem of eps averaging, I have used (set! > eps-averaging? false) in ctl file, and turned off basic eps averageing in > anisotropic_averaging.cpp, but when I use h5totxt to list the epsilon , I got > the following data > > 2.0164 > 2.0164 > 2.0164 > 2.0164 > 2.741150936030191 > 9.75 > 9.75 > 9.75 > 9.75 > 9.75 > there still exist some kind of averaging, It is equal to introduce a 2nm > layer of low eps-inf dispersive material if I set resulotion to 500 and a to > 1000 nm, which will apperently drop the neff vs. omega curve. Is there any > clue to fix this problem? > > > (define-param sz 3) ; size of cell in z direction > (define-param dpml 1) ; PML thickness > (set! geometry-lattice (make lattice (size no-size no-size sz))) > (define d-au 0.5) > (define die1 (make dielectric ( epsilon (* 1.42 1.42)))) > (set! eps-averaging? false) > (define omega_d (/ 1 0.138)) ; plasma frequency of Au in Drude model > > > (define Au ; definition of material dispersion > (make dielectric (epsilon 9.75) > (polarizations > (make polarizability > (omega 1e-20) (gamma (/ 1 13)) > (delta-epsilon (* (* omega_d omega_d) 1e+40))) > ))) > > > (set! geometry > (list (make block (center 0 0 0) > (size infinity infinity sz ) > (material die1)) > (make block (center 0 0 (- (/ sz 2) (/ d-au 2))) > (size infinity infinity d-au) > (material Au)) > > )) > > (set! pml-layers (list (make pml (direction Z) (side Low) (thickness dpml)))) > (set-param! resolution 500) > > (define-param fcen (/ 1 0.63)) > (define-param df 1) > (set! sources (list > (make source > (src (make gaussian-src (frequency fcen) (fwidth df))) > (component Hy) (center 0 0 (- (/ sz 2) d-au )) )) ) > > (define-param k-interp 19) > (define-param k-points (list (vector3 2 0 0) > (vector3 2.6 0 0) > )) > (set! k-points (interpolate k-interp k-points)) > > (run-k-points 120 k-points) > > > Sincerely! > > Liang Huo > >
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