Actually, the results are correct since you ran the LDOS tutorial simulation with a default notch size of 0 (no opening in the metal cavity). Since the light has nowhere to escape, the cavity factor of the mode is infinity thus causing harminv to return a large but spurious value. If you look carefully at the plot shown on the tutorial page, you will notice that the notch size varies from 0.25a to 0.4a (increments of 0.05a). The smaller the size of the opening, the larger the cavity factor will be and thus the longer you will have to run ldos calculation (at least one period of the decay as explained therein) to ensure that the Fourier-transformed fields have converged which is why we chose the smallest notch to be 0.25a.
Ardavan Oskooi On Wed, Aug 29, 2012 at 1:52 AM, liu <[email protected]> wrote: > Hi, everyone: > > In "Meep Tutorial/Local density of states", I run the example, but > I obtain different resuts. and it seems that the results are wrong. > The meep has been installed sucsessfully, and after "make check", the > meep has been check sucsessfully. > So, I do not know why I obtain the wrong results? > > below is the results obtained by meep, and the source file is from example > from "Meep Tutorial/Local density of states " > ------------------------------------------ > Meep progress: 149.4425/150.0 = 99.6% done in 600.7s, 2.2s to go > on time step 59781 (time=149.453), 0.0101537 s/step > harminv0:, frequency, imag. freq., Q, |amp|, amplitude, error > harminv0:, 0.700102195996347, 2.36067836357685e-11, -14828411332.9095, > 11.8736075861261, 11.8708502434205+0.255874202673824i, 2.84359341640423e-10 > run 0 finished at t = 150.0 (60000 timesteps) > ldos0:, -8584073561.70435 > Field time usage: > connnecting chunks: 0.0984089 s > time stepping: 577.27 s > communicating: 22.6382 s > Fourier transforming: 0.0195484 s > everything else: 3.08084 s > ----------- > Initializing structure... > Working in 2D dimensions. > Computational cell is 4 x 4 x 0 with resolution 200 > block, center = (0,0,0) > size (1.2,1.2,1e+20) > axes (1,0,0), (0,1,0), (0,0,1) > block, center = (0,0,0) > size (1,1,1e+20) > axes (1,0,0), (0,1,0), (0,0,1) > dielectric constant epsilon diagonal = (1,1,1) > Halving computational cell along direction y > time for set_epsilon = 0.796059 s > ----------- > ldos1:, 0.700102195996347, +nan.0 > run 1 finished at t = 0.0 (0 timesteps) > Elapsed run time = 606.828 s > Some deprecated features have been used. Set the environment > variable GUILE_WARN_DEPRECATED to "detailed" and rerun the > program to get more information. Set it to "no" to suppress > this message. > > > > _______________________________________________ > meep-discuss mailing list > [email protected] > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss >
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