Thursday, March 15, 2012

Task 5: Sim for Parallel Plates

Now I'm just going to see if I can capture near-field enhancement between two plates. I'm going to set up simulations where I vary the distance between the two plates and get the flux between them. I'm just looking for trends here; I don't know how to work out the units yet.
I implemented SiC plates. One plate has the noisy polarizations. The other doesn't. In 1D there is no enhancement. There is a ~10x enhancement in 2D as can be seen in the figure. 1 unit on the abscissa is 1 micron.
BUT, after careful examination, this result comes from the flux captured from the gaussian pulse that I had put in (The random current function didn't start with exactly zero initial fields). Also, I'm getting some reflections which can be seen from the negative parts of spectrum. Now when thinking about heat transfer, the other side should be 0K and be totally absorbing. The reflections can be explained as follows in heat transfer terms: the other side is gaining energy and re-emitting back to the source.
I'm going to reduce the amplitude of the noise to see if the reflections are reduced relative to the flux of the source.


  1. Hi, I like your blog. Thanks for the explanations. one question, how do you simulate the permittivity of SiC in meep? I know one can simulate dispersive materials in meep. But just want to know the parameters.

  2. Check this post Part 1 only deals with conversions.

  3. Sorry I'm not involved in this work any more. But I think found the code that made this to give you start.


    (set! geometry-lattice (make lattice (size 10 5 no-size)))

    (set! pml-layers (list (make pml (thickness 1))))

    (set-param! resolution 30)

    (define myAg (make dielectric (epsilon 1)


    (make polarizability

    (omega 1e-20) (gamma 0.0038715) (sigma 4.4625e+39))

    ; (make noisy-lorentzian-susceptibility

    ; (noise-amp 10) (omega 1e-20) (gamma 0.0038715) (sigma 4.4625e+39))

    ; (make polarizability

    ; (omega 0.065815) (gamma 0.31343) (sigma 7.9247))

    ; (make polarizability

    ; (omega 0.36142) (gamma 0.036456) (sigma 0.50133))

    ; (make polarizability

    ; (omega 0.66017) (gamma 0.0052426) (sigma 0.013329))

    ; (make polarizability

    ; (omega 0.73259) (gamma 0.07388) (sigma 0.82655))

    ; (make polarizability

    ; (omega 1.6365) (gamma 0.19511) (sigma 1.1133))


    (set! geometry (list

    (make block (center -2.5 0.5 0.0) (size 5 infinity infinity)

    (material myAg ))))

    (set! sources (list

    ;(make source

    ; (src (make gaussian-src (frequency 2.5) (fwidth 5)))

    ; (component Ex)

    ; (center 0 0 0))

    (make source

    (src (make gaussian-src (frequency 2.5) (fwidth 5)))

    (component Ex)

    (center -3 0 0))

    ; (make source

    ; (src (make continuous-src (frequency 2.5) ))

    ; (component Ex)

    ; (center -3 0 0))



    ;why don't i get an output when i put this ??

    ;(This must be done after specifying the

    ; geometry, sources, resolution, etcetera,

    ; because all of the field parameters are initialized when flux planes are created.)

    (define trans ; transmitted flux

    (add-flux 5.0 5.0 40

    (make flux-region (center 4 0.0 0.0) (size 0 5 0))


    (run-until 1000 (at-every 0.6 (output-png Ex "-Zc bluered")))

    ; (run-until 10

    ; (at-beginning output-epsilon)

    ; (to-appended "ex" (at-every 0.6 output-efield-z)))

    ; (run-sources+

    ; (stop-when-fields-decayed 50 Ex (vector3 4 0 0.0) 1e-3)

    ; (output-png Ex "-Zc bluered")

    ; )

    (display-fluxes trans)

  4. Hi Majid! Thank you so much for this information.