MultipleLayerTransmission - 0 T(2)*n(3)/n(2)];D3=[T(3) 0 0

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
%Chap4Exercise5.m%VCSEL mirror designclear;clf;% '1' is GaAs layer, '2' is AlAs layer % thickness of dielectric with refractive n1 (GaAs layer) % thickness of dielectric with refractive n1 in center of pass-band filtern=[1 1.38 2.4 1.7 1.52]; nlayer=4; %number of layers wavelength=550e-9;% center wavelength in metersd(1:nlayer+1)=0;d(2:4)=wavelength./n(2:4);for j=1:nlayerT(j)=2*n(j)/(n(j) +n(j+1));Reff(j)=(n(j)-n(j+1))/(n(j)+n(j+1));endistep=0;range=(400:1:700)*1e-9; %wavelength scanning rangefor wavelength=rangeistep=istep+1; k(2)=2*pi*n(2)/wavelength; %input from airk(3)=2*pi*n(3)/wavelength;k(4)=2*pi*n(4)/ wavelength;% in EM, exp(-ikz) is considered positive propagation +z direction% Assuming light coming in perpendicularly from the lower side (-z) to upper size (+z)% A*exp(-ik1*z)+B*exp(ik1*z)=C*exp(-ik2*z)+D*exp(-ik2*z)% D0,D1,D2 are interface matrices% [D0]*[input from air]=[D1]*[output to n1],% [D1]*[input from n1]=[D2]*[output to n2]D1=[T(1) 0 0 T(1)*n(2)/n(1)];D2=[T(2) 0
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 0 T(2)*n(3)/n(2)];D3=[T(3) 0 0 T(3)*n(4)/n(3)];D4=[T(4) 0 0 T(4)*n(5)/n(4)];R4= % P1,P2,P3 are propagation matrices% input from the below, output above material, [input from below]=[P]*[output above],P2=[exp(-i*k(2)*d(2)) 0 0 exp(i*k(2)*d(2))]; P3=[exp(-i*k(3)*d(3)) 0 0 exp(i*k(3)*d(3))];P4=[exp(-i*k(4)*d(4)) 0 % for dielectric with refractive index n1 in center of 0 exp(i*k(4)*d(4))]; % passband filter % Solution = % [Input A;B]=inv(D0)*{D1*P1*inv(D1)*D2*P2*inv(D2)}*{2nd period}*{3rd}% *. .*{defect,wider n1}*. ..*{D1*P1*inv(D1)*D2*P2*inv(D2)}*D0*[output C;D]Total=D1*P2*D2*P3*D3*P4*D4; % for period of lower mirrorr(istep)=Total(1,1)) % reflected electromagnetic fieldR(istep)=r(istep)*conj(r(istep)) % total reflection intensity is r x r*Teff(istep)=1-R(istep); % total reflection intensity is r x r*end %%% loop to next value of istepfigure(1);plot(range,r);grid; title(['Chapt4Exercise5b, VCSEL mirror' ]);ylabel('Reflection');xlabel('Wavelength (m)');...
View Full Document

This note was uploaded on 01/24/2011 for the course EE 256 at Stanford.

Ask a homework question - tutors are online