BOR-FDTD code verification

Hello,
I implemented a BOR-FDTD Code with Mur boundary conditions.
For verification purposes I want to simulate an optical fiber or a
circular waveguide. Is there a simple possibility to extract the
propagation constant for a certain mode or are there are other
more efficient methods for the verification of absorbing boundary
conditions ?
Any help appreciated.

Regards

hi. i've been doing BOR FDTD but i don't know if i'm doing the right way. can you give me a copy of your code? thnks

can i have the code of your bor-fdtd? i think in BOR FDTD only one mode calculated for every run. so if you want to calculate other modes you have to rerun it again. i'm not sure though but that's what i understand.