Hi Meep user
I am trying to simulate narrow band filter example in the PhC molding the
flow of light book, page 196-197, figure 4.
First question: I have obtained the resonance frequency=0.3786 and Q=510.
Although the dimension, pml and resolution are increased why I cannot get
the exact value?
Second question: According to the figure, 0.3765 frequency is not
transmitted but resonance frequency 0.3803 is transmitted. I have observed
the 0.3765 frequency is blocked in my simulation. But, neither the
resonance frequency 0.3786 (according to my calculation) nor 0.3803
(according to book) is transmitted. What I missed the point?
my ctl codes for Q and field transmittance are as the following
best…
Onder
------------------------------------
;; Q calculation
;; PhC Molding the flow of light, page 196-197 , Figure 4
(define-param nbase 1) ;air
(define-param epsbase (* nbase nbase))
(define-param epsrod 11.4) ;; rods
(define-param a 1)
(define-param r 0.2) ; rods radius
(define-param sx 25)
(define-param sy 15)
(set! geometry-lattice (make lattice (size sx sy no-size)))
(set! default-material (make dielectric (epsilon epsbase)))
(set! geometry (list
(make cylinder (center 0 0) (height infinity) (radius r)
(material (make dielectric (epsilon epsrod))))
))
(set! geometry (geometric-objects-lattice-duplicates geometry))
(set! geometry (append geometry
(geometric-object-duplicates (vector3 1 0) 0 10
(make cylinder (center 3 0) (radius r)
(height infinity)
(material (make dielectric (epsilon epsbase))))
)))
(set! geometry (append geometry
(geometric-object-duplicates (vector3 -1 0) 0 10
(make cylinder (center -3 0) (radius r)
(height infinity)
(material (make dielectric (epsilon epsbase))))
)))
(set! geometry (append geometry
(list
(make cylinder (center 0 0) (radius r) (height infinity) (material
(make dielectric (epsilon epsbase) ))
)
)))
(define-param fcen 0.38)
(define-param df 0.1)
(set! sources (list
(make source
(src (make gaussian-src (frequency fcen) (fwidth df) ))
(component Ez)(center 0 0)
)
))
(set! pml-layers (list (make pml (thickness 2.0))))
(set! resolution 32)
(run-sources+ 300
(at-beginning output-epsilon)
(after-sources (harminv Ez (vector3 0) fcen df)))
----------------------
----------------------
;; field transmission
;; PhC Molding the flow of light, page 196-197 , Figure 4
(define-param nbase 1) ;air
(define-param epsbase (* nbase nbase))
(define-param epsrod 11.4) ;; rods
(define-param a 1)
(define-param r 0.2) ; rods radius
(define-param sx 25)
(define-param sy 15)
(set! geometry-lattice (make lattice (size sx sy no-size)))
(set! default-material (make dielectric (epsilon epsbase)))
(set! geometry (list
(make cylinder (center 0 0) (height infinity) (radius r)
(material (make dielectric (epsilon epsrod))))
))
(set! geometry (geometric-objects-lattice-duplicates geometry))
(set! geometry (append geometry
(geometric-object-duplicates (vector3 1 0) 0 10
(make cylinder (center 3 0) (radius r)
(height infinity)
(material (make dielectric (epsilon epsbase))))
)))
(set! geometry (append geometry
(geometric-object-duplicates (vector3 -1 0) 0 10
(make cylinder (center -3 0) (radius r)
(height infinity)
(material (make dielectric (epsilon epsbase))))
)))
;;; hole at the center
(set! geometry (append geometry
(list
(make cylinder (center 0 0) (radius r) (height infinity) (material
(make dielectric (epsilon epsbase) ))
)
)))
(set! sources (list
(make source
(src (make continuous-src (frequency 0.3803) ))
(component Ez)(center -9 0) (size 0 1) (amplitude 1)
)
))
(set! pml-layers (list (make pml (thickness 2.0))))
(set! resolution 32)
(run-until 400
(at-beginning output-epsilon)
(to-appended "ez" (at-every 5 output-efield-z)))
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