On Mon, 7 May 2007, Florencio Garcia wrote: > Does anyone know how could I calculate the flow of photons with a > particular propagation direction that go through the detector > (flux-region) while ignoring those photons that also go through the > flux-region but have a different propagation angle? For example, say > that you have a diffraction grating and want to calculate the > transmission intensity of a particular diffracted order. Is it > possible to introduce a flux-region that can discriminate photons > with different propagation directions?
There is no built-in feature for this, I'm afraid. Again, this is one of the many things that will become easy once we support outputting the Fourier transform of the fields (as a function of space and frequency) in a sane, documented format. All you would need to do then would be to compute the discrete Fourier transform of the fields in space in the flux plane. Until then, your best option is to accumulate the Fourier transform in time of the fields, by yourself in the Scheme code, for a set of points in the flux plane, and then use these points to compute the spatial Fourier transform of the fields. Of course, if you are using a CW source, then you can just dump the fields to a file in the flux plane (use the in-volume output function) and compute the spatial FFT in Matlab. However, this discards the main advantage of time-domain simulation, the fact that you can put in a pulse and get the response at multiple frequencies simultaneously. Steven _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
