Dear all:
I use meep to obtain the band gap of a line waveguide. for one period, the
result is right.
But if the computational domain is include three
periods(the same air holes with one period), the result is quite different from
the one period.
is there any problems with my program?
Below is the
============================
; Some parameters to describe the geometry:
(define-param eps 11.56); dielectric constant of waveguide
(define-param w 0.45); width of waveguide
(define-param r1 0.35); radius of holes
(define-param r2 0.35); radius of holes
(define-param sy 5); size of cell in y direction (perpendicular to wvg.)
(define-param dpml 1); PML thickness (y direction only!)
(set! geometry-lattice (make lattice (size 1 sy no-size)))
(set! geometry (append
(list
(make block (center 0 0) (size infinity infinity infinity)
(material (make dielectric (epsilon eps))))
)
(geometric-objects-duplicates (vector3 0 (- 0 (/ 1.732 3)) )
0 4
(list
(make cylinder (center (/ 0.5 3) (/ (- (- w) r1) 3) )
(radius (/ r1 3) )
(height infinity)
(material air)
)
(make cylinder (center (- 0 (/ 0.5 3)) (/ (- (- w) r1) 3) )
(radius (/ r1 3) )
(height infinity)
(material air)
)
;;;; r1
;; middle holes
(make cylinder (center 0 (/ (- (- w) r1 0.866) 3) )
(radius (/ r1 3) )
(height infinity)
(material air)
)
;;;; r2
(make cylinder (center (/ 1.5 3) (/ (- (- w) r2) 3) )
(radius (/ r2 3) )
(height infinity)
(material air)
)
(make cylinder (center (- 0 (/ 1.5 3)) (/ (- (- w) r2) 3) )
(radius (/ r2 3) )
(height infinity)
(material air)
)
;; middle holes
(make cylinder (center (/ 1 3) (/ (- (- w) (/ (+ r1 r2) 2)
0.866) 3) )
(radius (/ (/ (+ r1 r2) 2) 3) )
(height infinity)
(material air)
)
(make cylinder (center (- 0 (/ 1 3)) (/ (- (- w) (/ (+ r1 r2)
2) 0.866) 3) )
(radius (/ (/ (+ r1 r2) 2) 3) )
(height infinity)
(material air)
)
)
)
;;;;
))
(set-param! resolution 30)
(set! pml-layers (list (make pml (direction Y) (thickness dpml))))
(define-param fcen 0.8); pulse center frequency
(define-param df 1.5);pulse freq. width: large df = short impulse
(set! sources (list
(make source
(src (make gaussian-src (frequency fcen) (fwidth df)))
(component Hz) (center 0.0434 -0.071))))
(set! symmetries (list (make mirror-sym (direction Y) (phase -1))))
;(set-param! k-point (vector3 0.4 0))
;(run-sources+ 300 (after-sources (harminv Hz (vector3 0.1234) fcen df)))
(define-param k-interp 49)
(run-k-points 300 (interpolate k-interp (list (vector3 0) (vector3 0.5))))
_______________________________________________
meep-discuss mailing list
[email protected]
http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
