Dear users,I have a ctl file for simulating the structure introduced at " prb.
73 041101 ".In this structure and some other ones that I have simulated, I
have noticed that the "D-conductivity" command in the "make dielectric" command
has no impact on the results. Since I have used copper in the simulation at a
narrow range of frequencies at GHz, I have taken the real part of permittivity
equal to 1 and the D-conductivity equal to "2.5e+7". What surprises me is that
there is no difference in the results when I set D-conductivity equal to zero
or when I set it equal to the previously mentioned or any other value. Does
anybody know why? I have attached the ctl file. Any comment will be
appreciated.Mehdi
; prb 2006, short wire pairs 1mu = 1mm
; parameters
; part one
(define-param ts .254) ; thickness of
substrate(define-param tw .01) ; thickness of
wire(define-param ww 1) ; width of the
wire(define-param lsw 7) ; length of short
wire(define-param ax 9.5) ; unit cell in x
direction(define-param ay 7) ; unit cell in y
direction(define-param az 2.274) ; unit cell in
z direction(define-param d 1) ; distance between
wires(define-param dpml 1) ; thickness of pml
layers
; part two
(define-param n 2.53) ; refractive index of
substrate (define-param c-sig 58e+6)
; conductivity of copper in Siemens per meter units (SI units)(define-param a
1e-3) ; meep unit in meters (1mu=1mm)(define-param
c 3e+8) ; speed of light in vacuum in SI
units(define-param eps-0 8.85e-12) ; epsilon in vacuum in
SI units(define-param c-eps 1) ; copper real
epsilon ; part three
(define-param mf (/ 1 300)) ; multiplication factor
(define-param s-freq 12) ; starting frequency in
GHz(define-param e-freq 16) ; ending frequency in
GHz(define-param nfreq 400) ; number of frequencies
for which the flux should be calculated
; define parameters
(define f1 (* s-freq mf)) ; starting frequency in meep
units(define f2 (* e-freq mf)) ; ending frequency in
meep units(define fcen (/ (+ f1 f2) 2))(define df (- f2 f1))(define c-sig-D (/
(* a c-sig) (* c c-eps eps-0))) ; D-conductivity of copper
; defined parameters , geometry lattice
(define sx ax) ;(define sy ay) ;(define sz (+ (* 2 dpml) (* az))) ;
(set! geometry-lattice (make lattice (size sx sy sz))) ;
; define materials
(define copper (make medium
(epsilon 1) (D-conductivity c-sig-D)
)) (define substrate (make dielectric
(epsilon (expt n 2)) ));
; for periodic boundary condition
(set! k-point (vector3 0 0 0)) ;(set! ensure-periodicity true) ;(set!
eps-averaging? false)
; for output
(use-output-directory);
; the materials
(define-param no-mat? false) ; if true, there will be no material
(set! geometry (if no-mat? (list (make
block (center 0 0 0) (size
ax ay az) (material vacuum) )
)
(list ; sub... (make block
(center 0 0 0) (size ax ay ts)
(material substrate)
) ; mk b.. ; short wire pair (make
block (center 0 0 (+ (/ ts -2) (/ tw -2)))
(size lsw ww tw) (material copper)
) ; mk b... (make block
(center 0 0 (+ (/ ts 2) (/ tw 2))) (size lsw ww tw)
(material copper) ) ; mk b...
; left long wire pairs
(make block (center 0 (+ (* -1 d)
(* -1 ww)) (+ (/ ts -2) (/ tw -2))) (size ax ww tw)
(material copper) ) ; mk b...
(make block (center 0 (+ (* -1 d) (* -1 ww))
(+ (/ ts 2) (/ tw 2))) (size ax ww tw)
(material copper) ) ; mk b...
; right long wire pairs
(make block (center 0 (+ d ww) (+
(/ ts -2) (/ tw -2))) (size ax ww tw)
(material copper) ) ; mk b...
(make block (center 0 (+ d ww) (+ (/ ts
2) (/ tw 2))) (size ax ww tw)
(material copper) ) ; mk b...
) ; list ex... mat... ) ; if no...) ; set geome...
; resolution and dpml
(set-param! resolution 10) ; (set! pml-layers (list (make pml (thickness dpml)
(direction Z)))) ;
; sources
(set! sources (list (make source (src
(make gaussian-src
(frequency fcen) (fwidth df) ) ; mk co...
) ; src (component Ex) (size sx sy 0)
(center 0 0 (+ (/ sz -2) dpml .5)) ) ; mk so...
) ; li...) ; set
; detectors
; transmitted flux
(define trans (add-flux fcen df nfreq (make flux-region
(center 0 0 (- (/ sz 2) dpml .5)) (size
sx sy 0) ) ; mk f..-r.. ) ; mk ad..) ; de...
; reflected flux
(define refl (add-flux fcen df nfreq (make flux-region
(center 0 0 (+ (/ sz -2) dpml .5)) (size
sx sy 0) ) ; mk f... ) ; add...) ; def...
(if (not no-mat?) (load-minus-flux "refl-flux" refl)) ; normalization purpose,
part 1
; running the sources
(run-sources+ (stop-when-fields-decayed 50 Ex
(vector3 0 0 (- (/ sz 2) dpml .5)) 1e-3
) ; sto..(at-beginning output-epsilon);(to-appended "ex" (at-every .6
output-efield-x ))) ; run-sources
; for normalization purposes, part 2
(if no-mat? (save-flux "refl-flux" refl));
; display fluxes
(display-fluxes trans refl)
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