Hi Badar, I have tried this as well in the past, but I would just redo the fit if I were you...much easier... You can always use the parameters you have as an initial guess. I have posted something on the forum some time ago, about how you can verify your fit in MEEP.
Best regards, Milan From: [email protected] [mailto:[email protected]] On Behalf Of badar ahmed Sent: woensdag 2 maart 2011 19:06 To: [email protected] Subject: [Meep-discuss] Converting dispersive material parameters Dear All, I am stuck on how exactly to convert the parameters that pertain to the fitting of the dispersive medium in SI units, to MEEP units: Eps(w) = a + b / (d -w^2 + j * C * w) where w = 3e14 *2*pi /lambda lambda is in micrometers (hence the w = 3e14). The parameters that I have DO fit the n and k values for the actual data for the sample. I converted them to MEEP units, from which I found the sigma, omega, Eps and gamma. I put the values into the dispersive medium model for the correct thickness of the sample, but upon generating the transmission spectrum by normalising to a pulse; the fringes seemed to be consistent with those of the actual sample, but the transmission was significantly under-predicted across the spectrum. The conversions I have done are: Eps stays the same Sigma stays the same Omega(meep) = sqrt(d).(a/(2*pi*c)) Gamma(meep) = C.(a/(2*pi*c)) where 'a' = lengthscale, 1 = 100 nm, hence 'a' = 1e-7 and c = 3e8 Could someone please tell me where I may be going wrong? Many thanks.
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