Photonic Bandgap with different positions of dipole




I have downloaded the simulation file from lumerical’s website ( to simulate photonic bandgap. I have modified the position of the dipole so that- only one dipole is emitting at the center of the structure. Then the band structure become discontinued. See the image below:

Anyone has any idea, why this is happening?

Thank you
square2D (1).fsp (6.3 MB)
square2D.fsp (6.3 MB)


The ‘missing’ parts of the modified bandstructure are probably due to the field pattern of the modes having a node at the position of the dipole. This means that they are not excited by the sole dipole, and as such do not show up in the search for resonances that computes the band diagram.
This problem is also why a dipole ‘cloud’ is usually used to ensure that all modes of interest are excited in the simulation.


In that case, if I want to simulate how a single implanted ion will behave inside a photonic structure, how I should position the electric dipole in lumerical?


HI @ntabassum

As @thsv mentioned, you may loose some of the resonant modes if you cannot excite them. This happens when the the dipole(s) is located at the node of the mode. Please visit the link below for more details on this regard:

If you want to obtain the band-structure plot, you will need to add more dipoles to the simulation region. However, if you want to know how an implanted ion will behave inside a photonic structure, you need to use a dipole source at exact location of implanted ion with same polarization and run the simulations. Then you can visualize the resonant modes or monitor the transmission.


Thanks @bkhanaliloo.
I found my answer within your earlier comment.


I am glad to hear that problem is resolved.

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