% Fig_3_3b % Essential Semiconductor Laser Device Physics % Fabry-Perot optical resonator clear all; clf; err=0.00001; c=3e8; %speed of light in vacuum [m s^-1] nr=3.3; %effective refractive index in cavity lambda0=1310e-9; %center emission wavelength [m] Lc=3e-6; %Cavity length [m] r1=0.95; %Reflectivity of mirror1 r2=0.95; %Reflectivity of mirror2 r=r1*r2; %Optical loss per photon round-trip %r=.8*.4; F=pi*r^0.5/(1-r) %Optical Finesse Fconst=(2*F/pi)^2; Imax=1/((1-r)^2); %Peak intensity inside cavity normalized to I0 f0=c*1e-12/lambda0 %center frequency in THz deltaf=c*1e-12/(2*Lc*nr) %THz deltawavelength=lambda0^2/(2*Lc*nr) %m; gamma_opt=deltaf/F Q=f0/gamma_opt for i=[1:1:10000] %x=f0*i*0.001; Frequency(i)=(f0+i*0.003); Fwavelength(i)=c/Frequency(i); x=sin(pi*Frequency(i)/deltaf); x2=x*x; Intensity(i)=Imax/(1+(Fconst*(x2))); %y(i)=sin(x*deltax) end %******************** plot figures ************************ figure(1); plot(Frequency,Intensity); %axis([f0,f0+1,0,5]); hold on; xlabel('Frequency, \nu (THz)'),ylabel('Intensity'); title(['\itr\rm_1 = ',num2str(r1,'%4.2f\n'),', \itr\rm_2 = ',... num2str(r2,'%4.2f\n'),', \itn\rm_r = ',... num2str(nr,'%4.1f\n'),', \itf\rm_0 = ',... num2str(f0,'%4.0f\n'),' THz, \itL\rm_C = ',num2str(Lc*1e6,'%4.1f\n'),... ' \mum, \lambda_0 = ',num2str(lambda0*1e6,'%4.3f\n'),' \mum']); hold off; figure(2); plot(Fwavelength*10^-6,Intensity); xlabel('Wavelength, \lambda (\mum)'),ylabel('Intensity'); title(['\itr\rm_1 = ',num2str(r1,'%4.2f\n'),', \itr\rm_2 = ',... num2str(r2,'%4.2f\n'),', \itn\rm_r = ',... num2str(nr,'%4.1f\n'),', \itf\rm_0 = ',... num2str(f0,'%4.0f\n'),' THz, \itL\rm_C = ',num2str(Lc*1e6,'%4.1f\n'),... ' \mum, \lambda_0 = ',num2str(lambda0*1e6,'%4.3f\n'),' \mum']);