Reflection and Transmission calculation for confined 1D PhC

I am able to calculate reflection and transmission for 1D PhC using plane wave source and periodic boundary condition.
Now I want to calculate R and T for confined structure. According to literature I have to use TFSF source with PML boundary condition for this structure but I am getting vague result.
can you please check my file and tell me the right procedure to simulate this structure.

Thank you
NareshDBR 1510 no cavity plane wave_test.fsp (344.3 KB)

Dear @nsplasma

I took a look at your simulation file and there are few concerns here:

If you put any monitor outside the TFSF region, it will capture only the scattered light. Thus, you want to make sure that T and R monitors are located inside the TFSF.

Since your DBR geometry is cut, you would expect to see a decent reflection on the facets of the geometry (DBR). To eliminate these reflection, please extend your geometry into TFSF and also the PML layer.

Most importantly, can you please explain why you are using TFSF source? If DBR is connected to a waveguide, say fiber, I recommend to use mode source. Please refer to Bragg microcavity KB example for how to set up your simulation.

Please keep me updated with your simulation and I am happy to help.


Thank you @bkhanaliloo
I want to see the effect of lateral dimension (Diameter) in reflection and transmission. I can not use the plane wave source because boundary condition is PML. So please tell me how to simulate this structure.


Hi @nsplasma

If your DBR is connected to an external waveguide, you can use a mode source. To do this, add two cylinders at two ends of DBR (one representing input and the other as output) with appropriate refractive index, and add Mode source.

If you don’t have a particular reason to use TFSF source, I guess Mode source would be the best option. TFSF source is useful if you want to study scattering from a material.