In OptiFDTD after modes calculation we get data like this:
[ Modes ] [ Modal Index ] [ Polarization ]
Mode 1 ( 1.35890436, 0.00000283 ) FVect TE
Mode 2 ( 1.35909016, -0.00000458 ) FVect TM
i want to know that what does modal index show?
How Effective refractive index is calculated in FDTD ?
Thanks