Function to reproduce Fig. 3.14(d) Wavelength-dependence of the reflection coefficient at theta_inc=36º for coupling to PSPPs at a silver/air interface with a sapphire prism using the Kretschmann ATR configuration. The effect of an adsorbate layer of varying thickness L_{ads} and refractive index nA=1.5 is modeled using a four-layer configuration: prism/metal/adsorbate/dielectric. Thickness of metal layer is 50 nm. This file is part of the SPlaC v1.0 package (copyright 2008) Check the README file for further information
0001 %%%%%%%%%%%%%%%%%% 0002 % Computations 0003 %%%%%%%%%%%%%%%%%% 0004 0005 % lambda in nm (column) 0006 lambda=transpose(500:0.5:1000); % [1001 x 1] 0007 0008 % angles in degrees 0009 aideg=36; % [1 x 1] 0010 0011 % metal thickness 0012 Lmetal=50; % in nm 0013 % thickness of adsorbed layer (in nm) 0014 Lads={0,1,2,3,5,10,50}; % cell of scalar elements 0015 nNbLads=length(Lads); 0016 0017 % calculate epsilon for silver 0018 eAg=epsAg(lambda); 0019 % refractive indices 0020 nP=1.766; % Sapphire - Prism 0021 nA=1.5; % Oil - Adsorbate layer ("effective refractive index") 0022 nM=1.0; % air - Dielectric 0023 0024 0025 % Initialize cell for reflectivity Rp (one cell element for each Lads) 0026 Rp=cell(1,nNbLads); 0027 0028 % Defines Krestschmann configuration with adsorbed layer, 3 interfaces, 4 layers 0029 % Prism/Metal/Adsorbate/Dielectric 0030 % all epsilons are column (lambda-dependent) 0031 nNbSurf=3; 0032 Cepsilon{1}=nP^2+0*lambda; % Prism 0033 Cepsilon{2}=eAg; % Metal 0034 Cepsilon{3}=nA^2+0*lambda; % Adosrbed layer 0035 Cepsilon{4}=nM^2+0*lambda; % Dielectric for PSPP 0036 CL{1}=0; % interfaces positions 0037 CL{2}=Lmetal; % Metal thickness 0038 0039 0040 % loop through each possible nM 0041 for ii=1:nNbLads 0042 CL{3}=Lads{ii}; % Adsorbate layer thickness 0043 % solves the problem for TM waves 0044 stResTM=PlnMultiRef ('TM',nNbSurf, lambda, Cepsilon, CL, aideg); 0045 % extract reflectivity for this Lads: rP is [1001 x 1] 0046 Rp{ii}=abs(stResTM.rP).^2; 0047 end 0048 0049 %%%%%%%%%%%%%%%%%% 0050 % Drawing 0051 %%%%%%%%%%%%%%%%%% 0052 0053 % create, position, and resize figure 0054 scrsz = get(0,'ScreenSize'); % scrsz(3) contains screen width 0055 figAspectRatio=1.5; 0056 figWidth=3/4*scrsz(3); 0057 figure('Name','Fig. 3.14(d)', ... 0058 'Position',[(scrsz(3)-figWidth)/2 scrsz(4)-150-figWidth/figAspectRatio figWidth figWidth/figAspectRatio]); 0059 0060 % create plot 0061 plot(lambda,Rp{1},lambda,Rp{2},lambda,Rp{3},lambda,Rp{4},lambda,Rp{5},lambda,Rp{6},lambda,Rp{7}); 0062 title('Air/Ag PSPP excitation in the Kretschmann configuration with an adsorbed layer - L_{metal}=50 nm, \theta_{inc}=36^\circ'); 0063 % format graph 0064 axis([500 1000 0 1.15]); 0065 xlabel('Wavelength [nm]'); 0066 ylabel('Reflectivity'); 0067 legend('L_{ads}=0 nm','L_{ads}=1 nm','L_{ads}=2 nm','L_{ads}=3 nm', ... 0068 'L_{ads}=5 nm','L_{ads}=10 nm','L_{ads}=50 nm','Location','East'); 0069 0070 0071 0072 0073