Learning Forum

[areegabd]

Hello everyone

I want to study the emission rate for my structure which is made of a hexagonal array of a dimer. I should place my dipole at the center of the hexagonal array. how can I have a periodic array?

best

Areej

[Kyle]

The Triangular, FCC, BCC Photonic Crystal Bandstructure example (https://support.lumerical.com/hc/en-us/articles/360041566734) demonstrates how to set up periodic boundary conditions for a triangular lattice, which I believe should be the same as your hexagonal lattice:

[areegabd]

Dear ,
Thank you so much for your response, in fact that what I depended on when I create my array which I attached a screenshot of and I used periodic boundary along x and y. I want to make sure if it is correct or not.
Best
Areej

[Kyle]

Ansys staff can't download attachments from the ALF, can you please copy and paste your image directly into the message, like I did in my post?
One way to tell if the image is correct is to create a geometry with multiple periods, then move the simulation region over one period in x or y. The simulation region should appear the exact same for a periodic geometry if the region is set up properly.

[areegabd]

Thank you again for your response, I did as you said and I run it with multiple periods, see the images, can you tell me are the result correct?


I run both cases and calculated the decay rate and the results were:
Thanks again, and I am looking forward to here back from you.

[Kyle]

Sorry, I've realized I misunderstood your original post. To study the emission from a quantum emitter like this we actually don't want to use periodic boundary conditions. When periodic boundaries are used, it is assumed that both the structure and the source are periodic, so this would model a periodic array of emitters. With periodic boundary conditions the results would include the coherent interference between the emitters in each unit cell, which would not be accurate as the emitters will be incoherent.
Instead of periodic boundary conditions, multiple unit cells should be included in the simulation region with PML boundaries. While this won't model an infinitely periodic structure, as long as enough unit cells are included the results should closely approximate a periodic structure. It looks like your non-periodic boundary simulation uses this approach, so these results would be more accurate.
I would recommend that you take a look at our OLED/LED Application Gallery examples for more details, they use a similar methodology. For example:
OLED methodology: https://support.lumerical.com/hc/en-us/articles/360042225754
OLED (2D): https://support.lumerical.com/hc/en-us/articles/360042225934
3D OLED with hexagonal lattice symmetry: https://support.lumerical.com/hc/en-us/articles/360042219294
Sorry again for the confusion. Let me know if you have any questions.

[areegabd]

Dear Thank you so much for your Help.
Best
Areeg