Dear meep users,
I am trying to model a gaussian THz pulse in meep and am somehow not
really successfull. My simulation worked well with IR, so I don't think
the rest of the code can be the problem.
My unit of length is 1um. So the t_FWHM of my THz pulse is 30 in meep
units, when 100fs long. The center frequency is 10THz, thus 0.03333 in
meep units. I define t_0 as 200fs, thus 60 in meep units, phi_ce=0 and
E_0=1.
Now I define me gaussian pulse:
(define (gauss-pulse time) (* E_0 (exp (- (* 0.0+i (+ (* (* 2 const_pi
f_0) time) phi_ce)) (/ (* (- time t_0) (- time t_0)) (* 2 (/ t_fwhm
2.35482) (/ t_fwhm 2.35482)))))))
I use it with this command:
(set! sources (list (make source (src (make custom-src (src-func
gauss-pulse)))(component Ex)(center 0 1.300)(size 2.400 0))))
When I run my simulation until 500 with 200 resolution, I get a pulse
for a few cycles and then the sources just gets stuck at a certain
point, meaning the area of my linesource stays blue when transformed
into pngs using the h5topng command with color scheme dkbluered.
It also looks like almost no field is really coupled out from the
source, but it is only oscillating around the source.
Is the low frequency of the THz the problem?
How can I fix it?
Thanks a lot in advance!
Stefan
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