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; Meep Tutorial: Hz-polarized transmission and reflection through a cavity
; formed by a periodic sequence of holes in a dielectric waveguide,
; with a defect formed by a larger spacing between one pair of holes.
; This structure is based on one analyzed in:
; S. Fan, J. N. Winn, A. Devenyi, J. C. Chen, R. D. Meade, and
; J. D. Joannopoulos, "Guided and defect modes in periodic dielectric
; waveguides," J. Opt. Soc. Am. B, 12 (7), 1267-1272 (1995).
; Some parameters to describe the geometry:
(define-param eps 13) ; dielectric constant of waveguide
(define-param w 1.2) ; width of waveguide
(define-param r 0.36) ; radius of holes
; The cell dimensions
(define-param sy 12) ; 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
(list (make block (center 0 0) (size infinity w infinity)
(material (make dielectric (epsilon eps))))
(make cylinder (center 0 0) (radius r) (height infinity) (material air))))
(set! pml-layers (list (make pml (direction Y) (thickness dpml))))
(set-param! resolution 20)
(define-param fcen 0.25) ; 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 0.1234 0))))
(set! symmetries (list (make mirror-sym (direction Y) (phase -1))))
(define-param kx false) ; if true, do run at specified kx and get fields
(define-param k-interp 19) ; # k-points to interpolate, otherwise
(if kx
(begin
(set! k-point (vector3 kx))
(run-sources+
300 (at-beginning output-epsilon)
(after-sources (harminv Hz (vector3 0.1234 0) fcen df)))
(run-until (/ 1 fcen) (at-every (/ 1 fcen 20) output-hfield-z)))
(run-k-points 300 (interpolate k-interp (list (vector3 0) (vector3 0.5)))))
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