Can i use periodic boundary condition to find a mode in a simple silicon rib of 500nm*220nm waveguide?
Can you please elaborate on your inquiry? Why do you want to use periodic BCs?
I am trying to simulate one already published research article. In that article, they have optical mode in some silicon based hollow kind structure (same like rib) . I am not able to get same mode with pml or metal boundary condition. But it works for periodic BC. That is why i raised this query
Periodic boundary conditions can be used for periodic structures. Is your structure periodic?
Maybe you can share the simulation file and paper with me for a review?
Any quantity which has certain repetition is periodic. Similar to this, continuous silicon rib is also periodic structure (with undefined period). That is the reason i am little bit confused about this.
I am not still quite sure what your structure is. If you are simulating a structure like a photonic crystal fiber, you need to simulate the entire structure:
We use MODE to calculate the the supported modes in the cross section of waveguide. While the waveguide is infinitely long along the direction of propagation, it has a finite cross section and boundaries are generally set to metal or otherwise PML if you want to calculate the loss.