On Mon, 26 Nov 2007, Giovanni Pellegrini wrote: > now in a recent publication (chemical physics letter 446 (2005) 115-118) an > efficient parametrization of silver and gold dielectric function has been > introduced, which is similar to the MEEP one, except for the additional term > of the form: > > sigma/(i w eps_0) > > that this with a simple omega at the first power at the denominator. > > There is a way to introduce such a frequency dependence in a the MEEP > dielectric function?
This is just a simple frequency-independent conductivity term. It would certainly be possible to implement in Meep, but it's not supported directly right now. (I have to admit that metals have not been a major focus of ours, in part because I don't think FDTD is the best tool for simulating imperfect metallic materials.) It might be possible to model this in Meep by using a large value of gamma and sigma so that the quadratic terms are negligible. I'm not sure if this would have stability problems however. Alternatively, if you only are operating in a certain bandwidth, the best approach is to find a simple fit for the dielectric function in that bandwidth (rather than trying to use some function that fits over a wide bandwidth that you don't need). Regards, Steven G. Johnson _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
