Sellmeier Dispersion Formula

Matlab code for dispersion calculation

function  rn  = Sellmeier(a,wvln)
% Sellmeier  
% 
%    Sellmeier(A,WVLN) returns a matrix whose elements are the
%                   refractive indices calculated using the Sellmeier
%                   dispersion formula.
%
%     Sellmeier(A)     returns the refractive index at 0.58756 (n_d) 
%  
%          A     vector of Sellmeier coefficients
%       WVLN     vector of wavelengths (microns)
%
%
 if (nargin<2) 
    wvln = [0.58756];
 end
 ws = wvln.*wvln;
 rn = sqrt(1.0+a(1)*ws./(ws-a(4))+ a(2)*ws./(ws-a(5))+a(3)*ws./(ws-a(6)));

Example Calculation

>> a = [1.03961212 0.231792344 1.01046945 0.00600069867 0.0200179144 103.560653];
>> wvl = [ 0.48613 0.58756 0.65627];
>> Sellmeier(a,wvl)

ans =

    1.5224    1.5168    1.5143

>> format long

>> rn = Sellmeier(a,wvl)

rn =

   1.52237648507410   1.51680010973989   1.51432242520311

>> abbe = (rn(2)-1)/(rn(1)-rn(3))

abbe =

  64.1664

Maintained by John Loomis, last updated 12 Sept 2001