On Fri, 3 Dec 2010 16:42:11 +0100, "Marell, M.J.H." <[email protected]> wrote: > If I’m not mistaking , this only works for dispersive media of which the > real part is positive, because for negative epsilon you just get > exponential decay > There is way to verify your material: > http://www.mail-archive.com/[email protected]/msg03527.html > > Best regards, > > Milan > >
Thanks for the nice example - I also have found the example in the tutorial a bit confusing: as far as I understand it now, the material definition given at the beginning of http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Material_dispersion (set! default-material (make dielectric (epsilon 2.25) (E-polarizations (make polarizability (omega 1.1) (gamma 1e-5) (sigma 0.5)) (make polarizability (omega 0.5) (gamma 0.1) (sigma 2e-5)) ))) should correspond to a dispersion function epsilon = 2.25 + (1.1^2)*0.5/(1.1^2 - f^2 - i*f*1e-5) + (0.5^2)*2*1e-5/(.5^2 - f^2 - i*f*0.1) or in Latex notation \varepsilon \left( f \right) = 2.25 + \frac{{1.1^2 \cdot 0.5}}{{1.1^2 - f^2 - if \cdot 10^{ - 5} }} + \frac{{0.5^2 \cdot 2 \cdot 10^{ - 5} }}{{0.5^2 - f^2 - if \cdot 0.1}} and not to the formula with the divisions by 2*pi as in the webpage. Excuse me if I repeat something that has already been said but the point seems rather important to me. Am I missing something simple or is the formula for epsilon(f) that appears in the tutorial wrong? Giovanni -- ================================================ Giovanni Piredda Postdoc - AK Hartschuh Phone: ++49 - (0) 89/2180-77601 Fax.: ++49 – (0) 89/2180-77188 Room: E2.062 ---------------------------------------- Message sent by Cup Webmail (Roundcube) _______________________________________________ meep-discuss mailing list [email protected] http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
