> Dear everyone, > > I am trying to generate oblique gaussion pulse in free space. > Periodic boundary condition is used. > However, I got negative flux at some angle and frequency. For example, I > am generating a oblique gaussion pulse with inicdent angle of pi/3. > > flux1:, 0.15, 4.65957186638718e-4 > flux1:, 0.16, 0.00665869960300722 > flux1:, 0.17, -0.171534843068116 !!!!!!!!!!!!!!!!!!!!! > flux1:, 0.18, 73.2845322909382 > flux1:, 0.19, 397.820725296197 > flux1:, 0.2, 802.561622572833 > flux1:, 0.21, 672.922193722605 > flux1:, 0.22, 245.763362326864 > flux1:, 0.23, 40.1662550771828 > flux1:, 0.24, 2.83501384649874 > flux1:, 0.25, 0.0967463498182228 > > The flux at frequency 0.17 is negative. The png file shows the oblique > incidence looks fine. Can anyone point out the problem here? > > I am only interested in the flux of the central frequency. > > The ctl file is attached. > > > > > ; characteristic length 100 nm > (define-param N 1) ; N*N is the cylinder number > (define-param d 8) ; defect center spacing (ordinary spacing = 1) > (define-param L 15) ;length of the cylinder > (define-param r 1) > (define-param lam 5 ) > (define-param pad 1 ) > (define-param dpml (* 1.2 lam)) > (define-param sx (* N d)) > (define-param sy (* N d)) > (define-param sz (* 2 L)) > (define-param fce (/ 1 lam)) > (define-param df .1) > (define-param nfreq 11) > (define-param Ree 3) ; real part of epsilon > (define-param Ime 2) ; imaginary part of epslion > (define-param SimgaD (/ (* (* fce (* 2 pi)) Ime) Ree)) ; D-conductivity > > (set! geometry-lattice (make lattice (size sx sy sz))) > > (define theta (* 4 (/ pi 12))) > (define ky (* fce (sin theta))) > > (set-param! k-point (vector3 0 ky 0)) > (define (my-amp-func p) (exp (* 0+2i pi ky (vector3-y p)))) > > (set! resolution 10) > (set! sources (list > (make source > (src (make gaussian-src > (frequency fce) (fwidth df))) > (component Ey) > (center 0 0 (- (+ dpml pad) (/ sz 2)) ) (size sx sy 0) > (amp-func my-amp-func)))) > > (set! pml-layers (list (make pml (direction Z) (thickness dpml)))) > ;(set! symmetries (list (make mirror-sym (direction Y) (phase -1)))) > (define inc > (add-flux fce df nfreq > (make flux-region > (center 0 0 -1) (size sx sy 0)))) > > (run-sources+ 100 > (at-beginning output-epsilon) > (to-appended "Ey_void" (at-every 8 output-efield-y))) > (save-flux "inc-flux" inc) > (display-fluxes inc) >
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