Reply To: How to simulate the phase-shifted bragg grating in 3D FDTD?

[Kim Kang Seok]

Hello, Dimitris.

 

I'm trying to conduct the convergence test along with the mesh size.

 

It was interesting that the reflection intensity recorded a deep valley when the y of mesh size decreased to 5nm from 25nm.

In the theory of bragg grating, the corrugation width influences the reflection due to the coupling coefficient. And I supposed that decreasing x mesh means a detail propagating light in structure leading to a peak conclusively.

But the result makes me stuffy because it still doesn't show a resonance peak and lower reflection again in my simulation. In that running, I set the mesh size to 7.75nm of x mesh and 5nm of y mesh. One thing that I am concerned about is the simulation status of 3, and the simulation time is 5000fs. But, it requires much time to run the simulation

 

The below screenshots show the region of the phase-shifted grating waveguide and FDTD divided by the input, phase-shifted region, and output. The input and output parts are posted on the upper page.

I think there are no problems with the physical setting.
Thank you for your great interest again.

Kind regards

Dimitris