> > You can find the formula in lots of publications relating with the > transmission property of metallic nanohole arrays. The following link gives > one of the most important: > > http://www.opticsinfobase.org/josab/abstract.cfm?uri=josab-16-10-1743 > > Periodicity plays an important role in the ultimate result. i, j are the > scattering orders in the two directions, say X- and Y-axis. > > Tony Ok - thanks. I am a bit fuzzy on the details, and I need to think about it more ( I will write when I am done thinking ;-) ) but my feeling is that the formula you give is an equation for lambda once that you know the form of epsilon(lambda). That is, epsilon are not constants in that formula and you have to solve the equation lambda_SP = a / sqrt ( i^2 + j^2 ) * sqrt ( epsilon(Au, lambda_SP) * epsilon(dielectric) / ( epsilon(Au, lambda_SP) + epsilon(dielectric ) ) ) where epsilon(Au, lambda_SP) is the dielectric function of gold evaluated at lambda_SP. I need to write down the formulae to make sure that I have all the details right, but it *should* be like this: at normal incidence you are phase matched to all of the waves that are in the Brillouin point of the crystal at k_parallel = 0; in fact this point depends only on the projection of the wavevector k of the incident light parallel to the surface (which is again zero for all frequencies, since we are at normal incidence);you have to figure out if any of these waves corresponds to a surface plasmon, and there you use the formula for the wavevector of the SP given in the paper, which in wavelength dependent through the wavelength dependence of the dielectric constant of gold, thereby resulting in an equation for the wavelength, which when simplified results in equation 3 of the paper. At least this is how I would reason. But I would need to write down the formulae on a piece of paper to make sure that I understood correctly. In the meantine, if you are able to verify/disprove my reasoning above, please let me know. I hope that all of the symbols that I used in the notation are clear :-) Giovanni ---------------------------------------- Message sent by Cup Webmail (Roundcube) -- ================================================ 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
