[求助]meep的一个问题

离线magickun

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注册：2010-03-08
登录：2011-04-27
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0楼发表于: 2010-03-09 11:07:58

我想用meep模拟一下光纤端面的反射律，可是结果感觉不对，不知道哪里出错了。
二维的模拟
附件中是自己写的程序，原先是ctl格式的，为了方便上传改 ..

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附件:

new.txt (3 K) 下载次数:14

离线magickun

UID ：54004

注册：2010-03-08
登录：2011-04-27
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等级：仿真新人

1楼发表于: 2010-03-09 11:08:45

; a=100 nanometer
(define a 100)
(define r 2) ;radius of nanowire
(define h 50)
(define pad 5)
(define dpml 10) ; thickness of pml
(define lamda1 500) ;original wavelength 500nm
(define lamda2 850) ;alternate wavelength 850nm
;(define onewavelength ( / ( + lamda1 lamda2) ( * a  2)))
;(define distance ( * 1 onewavelength) )
(define distance 5)

;define material type
(define PMMA (make dielectric (index 1.59)))
(define tullurite (make dielectric (index 2.05)))
(define Ning (make dielectric (index 2.45)))

(define sx ( + h ( * 2 dpml))) ; size of cell in X direction
(define sy ( * 2 ( + pad dpml r))) ;size of cell in Y direction
(define sz ( * 2 ( + pad dpml r))) ;size of cell in Z direction
(set! geometry-lattice (make lattice (size sx sy sz)))

(set! geometry
    (if flag
    (list
    (make cylinder (center ( * -1 distance) 0) (radius r) (height h) (axis 1 0 0) (material Ning)))
    (list
    (make cylinder (center 0 0) (radius r) (height h) (axis 1 0 0) (material Ning)))))

(define fcen ( / ( * a ( + lamda1 lamda2)) 2 lamda1 lamda2))
(define df ( - ( / a lamda1) ( / a lamda2)))

(define scenter ( + ( * -0.5 h) distance)) ;source position
(define ssize ( * 3 r)) ;soueces size
(set! sources (list
    (make source (src (make gaussian-src (frequency fcen) (fwidth df)))
    (component Ey)
    (center scenter 0 0)
    (size 0 ssize ssize))))

(set! symmetries (list (make mirror-sym (direction Y) (phase -1))))

(set! pml-layers (list (make pml (thickness dpml))))
(set-param! resolution 10)

(define nfreq 300) ; number of frequencies at which to compute flux

(define rcenter ( - (* 0.5 h) ( * 1.2 distance))) ;refl position
(define fluxsize ( * 3 r)) ;flux size
(define refl ; reflected flux
    (add-flux fcen df nfreq
    (make flux-region
    (center rcenter 0 0) (size 0 fluxsize fluxsize))))

(if flag (load-minus-flux "refl-flux" refl))

(run-sources+
    (stop-when-fields-decayed 50 Ey (vector3  rcenter 0 0) 1e-3)
    (at-beginning output-epsilon))
;    (to-appended "ey" (at-every 5 output-efield-y)))

(if (not flag) (save-flux "refl-flux" refl))

(display-fluxes refl)