Lyot Filter transmisison as a function of wavelength

From Optical Imaging and Spectroscopy (Wiley - OSA 2009)
By David J. Brady
www.opticalimaging.org
Figures 9.33 and 9.34

Dn=0.2;
d=2/Dn;
Phi[lambda_]=Pi Dn d/lambda;

aplot=Plot[{Cos[Phi[lambda]]^2,Cos[2 Phi[lambda]]^2,Cos[Phi[lambda]]^2 Cos[2 Phi[lambda]]^2 +1},{lambda,.5 ,1.5},Axes->False, Frame->True,PlotStyle->{Black},PlotPoints->50,FrameTicks->{{None,None},{Automatic,None}},PlotLabel->"(a)"]

Dn=0.2;
d=2/Dn;
Phi[lambda_]=Pi Dn d/lambda;
bplot=Plot[{Cos[Phi[lambda]]^2 Cos[2 Phi[lambda]]^2 Cos[4Phi[lambda]]^2 Cos[8Phi[lambda]]^2},{lambda,.5 , 1.5},Axes->False, Frame->True,PlotStyle->{Black},PlotPoints->50,PlotRange->All,PlotLabel->"(b)"]

Dn=0.2;
d=2/Dn;
Phi[lambda_,Dnp_]:=Pi Dnp d/lambda;
filterF[lambda_,Dnp_]:=Cos[Phi[lambda,Dnp]]^2 Cos[2 Phi[lambda,Dnp]]^2 Cos[4Phi[lambda,Dnp]]^2 Cos[8Phi[lambda,Dnp]]^2 Cos[16Phi[lambda,Dnp]]^2 ;
cplot=Plot[{filterF[lambda,.195],filterF[lambda,.2],filterF[lambda,.205]},{lambda,.9 , 1.1},Axes->False, Frame->True,PlotPoints->50,PlotRange->All,PlotStyle->{Black},FrameLabel->{λ/(Subscript[λ, o])},PlotLabel->"(c)"]

Show[GraphicsArray[{{aplot},{bplot},{cplot}}]]

Dn=0.2;
d=2/Dn;
Phi[lambda_,Dnp_,theta_]:=Pi Dnp d /lambda;
filterF[lambda_,Dnp_]:=Cos[Phi[lambda,Dnp]]^2 Cos[2 Phi[lambda,Dnp]]^2 Cos[4Phi[lambda,Dnp]]^2 Cos[8Phi[lambda,Dnp]]^2 Cos[16Phi[lambda,Dnp]]^2;
thetaplot=DensityPlot[filterF[1+dL,.2 Cos[Pi theta/180]],{theta,-30, 30},{dL,-0.1,0.05},Axes->False, Frame->True,PlotPoints->50,PlotRange->All,FrameLabel->{Δθ,Δλ},ColorFunction->Function[{dt,tl,z},GrayLevel[z]]]