Hi Charlampos, The version I use is 1.2.1 which just released few days ago. I know how to define dispersive material in MEEP but what I want is to get the epsilon vs frequency as calculate in http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Material_dispersion. Thanks a lot for helping! Regards,Allen
Date: Mon, 14 Apr 2014 13:24:44 +0300 Subject: Re: [Meep-discuss] How to get material dispersion for metal From: iph...@gmail.com To: falcon_dai...@hotmail.com CC: meep-discuss@ab-initio.mit.edu First of all, which version of meep are you using? Here is my code for dispersive Ag:; Parameters(define a 100e-9) ; define the unit of length in meters (define cc (/ (* 2 (* pi 3e+8)) a)) ; unit of frequency in meep; eV->radpersec(define (ev->radpersec l) (/ l 6.5821e-16) ; divide by the reduced Planck's slab ) ; Ag; Parameters from http://arxiv.org/pdf/0911.2737.pdf(define Ag_epsb 3.7)(define Ag_wp (/ (ev->radpersec 9.2) cc)) (define Ag_gamma (/ (ev->radpersec 0.02) cc)) (define Ag (make dielectric (epsilon Ag_epsb) (E-susceptibilities (make drude-susceptibility (sigma 1.0) (omega Ag_wp) (gamma Ag_gamma) )))) Then, write (material Ag) in your geometry definition.. Regards, Charalampos On Mon, Apr 14, 2014 at 11:12 AM, Allen Spencer <falcon_dai...@hotmail.com> wrote: Dear Meep users, I am a beginner of MEEP. I am wondering to know how to calculate the material dispersion for metallic material like gold and silver as shown in the Tutorial http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Material_dispersion. I tried to use the same method as given in the tutorial but it seems that the source doesn't work in a PEC like material. Here is my code: (set! geometry-lattice (make lattice (size no-size no-size no-size))) (set-param! resolution 200)(set! default-material(make dielectric (epsilon 1)(E-polarizations (make polarizability(omega 1e-20) (gamma 0.038715) (sigma 4.4625e+41)) (make polarizability(omega 0.65815) (gamma 3.1343) (sigma 7.9247))(make polarizability(omega 3.6142) (gamma 0.36456) (sigma 0.50133))(make polarizability(omega 6.6017) (gamma 0.052426) (sigma 0.013329)) (make polarizability(omega 7.3259) (gamma 0.7388) (sigma 0.82655))(make polarizability(omega 16.365) (gamma 1.9511) (sigma 1.1133)))))(define-param fcen 0.5) (define-param df 0.5)(set! sources (list (make source (src (make gaussian-src (frequency fcen) (fwidth df))) (component Ez) (center 0 0 0)))) (define-param kmin 0.1)(define-param kmax 1)(define-param k-interp 99)(define kpts (interpolate k-interp (list (vector3 kmin) (vector3 kmax)))) (define all-freqs (run-k-points 200 kpts)) ; a list of lists of frequencies 20) (map (lambda (kx fs) (map (lambda (f) (print "eps:, " (real-part f) ", " (imag-part f) ", " (real-part (sqr (/ kx f))) "," (imag-part (sqr (/ kx f))) "\n")) fs)) (map vector3-x kpts) all-freqs) In Aaron Webster's note, meep-fields-analtic-chi1 has been used but in the newest version, I didn't find it. Can anyone tell me how to solve this problem? Thanks in advance! Regards Spencer _______________________________________________ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
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