Re: Effective epsilon used for each polarization

On Sun, 1 Oct 2006, Minghui Han wrote:
> Thanks Steve. I actually already tried to output both E and D, but then 
> the epsilon inferred from D/E varies for different Bloch modes. Since 
> what I want is the actual epsilon for Ex and Ey used in MPB, and I also 
> want it to be the same for all Bloch modes for a given structure, do you
> think it is possible to implement the smoothing method externally by 
> myself, just following what is described in your MPB paper and Meade's 
> 93 paper?

First off, I should apologize - I confused this with the Meep mailing 
list, so I mis-answered your question.  MPB does indeed output the full 
dielectric tensor: do an 'h5ls' on epsilon.h5 and you will see all of the 
tensor components.  Also, there is no Yee grid or interpolation in MPB, so 
this is not an issue.

Second of all, you are inferring epsilon incorrectly if you think it is 
different for different Bloch modes.  MPB (and Meep) uses the same epsilon 
tensor regardless of the field pattern.  You're perhaps confused by the 
fact that epsilon is a *tensor*, so you can't infer it merely by dividing 
D/E.  (You need 3 D's and 3 E's at a given point to infer the tensor.)

It is certainly possible to implement the smoothing method by yourself, 
but it shouldn't be necessary.

Steven