Spatially incoherent dipole

The response to a spatially incoherent sources can be obtained from the results of multiple coherent simulations.

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Solvers: FDTD, VarFDTD

Associated files:
usr_incoherent_dipoles.fsp (17.9 KB)
usr_incoherent_dipoles.lsf (2.0 KB)

Simulation with two dipoles

Two dipoles are simultaneously excited in a single simulation. As the FDTD simulation is inherently coherent, the interference pattern of the radiated fields by the two dipoles is clearly visible in both the movie monitor (linear scale) and frequency monitor (log scale).

temp1_movie_S1S2     image

Two simulations with a single dipole

Here are the results when only the top or the bottom dipole is excited.

temp2_movie_S1     image

temp3_movie_S2      image

Obtaining coherent and incoherent results from single-dipole simulations

If you coherently sum the results from the two simulations using each dipole, you get the same (coherent) result as in the simulation using two dipoles.

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If you incoherently sum the results, you can get the following result where the interference pattern is no longer observable.

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