ticks={{{-4π,"-((2  λ)/d)"},{-2π,"-(λ/d)"},0,{2π,"(λ/d)"},{4π,"((2  λ)/d)"}},Automatic};

Youngův pokus na dvojštěrbině

Plot[((1+Cos[x])/2),{x,-5π,5π},LabelStyle->Medium,AxesLabel->{"sin θ","I"},Ticks->ticks,ImageSize->600,PlotRange->{0,1},PlotStyle->Thick]

Difrakční mřížka

Manipulate[Plot[(1/(n^2))(((((Sin[n (x/2)])/(Sin[(x/2)]))))^2),{x,-5π,5π},LabelStyle->Medium,AxesLabel->{"sin θ","I"},Ticks->ticks,ImageSize->550,PlotRange->{0,1},PlotStyle->Thick],
{{n,5,Dynamic["n = "<>ToString[n]]},2,20,1},SaveDefinitions->True]

Štěrbina konečné šířky

Plot[(((((Sin[(x/2)])/(x/2))))^2),{x,-7π,7π},LabelStyle->Medium,AxesLabel->{"sin θ","I"},Ticks->ticks,ImageSize->600,PlotRange->{0,1},PlotStyle->Thick]

Kruhový otvor

p=Plot[{4(((((BesselJ[1,(x/2)])/(x/2))))^2),(((((Sin[(x/2)])/(x/2))))^2)},{x,-7π,7π},LabelStyle->Medium,AxesLabel->{"sin θ","I"},Ticks->ticks,ImageSize->600,PlotRange->All,PlotStyle->{{Thick,Red},{Darker[Blue],Thin,Dashed}}];
GraphicsRow[{p,Show[p,PlotRange->{0,0.2}]},ImageSize->1000]

Limit[(((((BesselJ[1,x])/x)))^2),x->0]

Plot[{BesselJ[1,x],(1/2)Sin[x]},{x,0,10π},ImageSize->600,PlotStyle->{{Thick,Red},{Thin,Dotted,Darker[Blue]}}]

Dvě štěrbiny konečné šířky

Manipulate[
Plot[Evaluate[{((Cos[α(x/2)])^2)(((((Sin[(x/2)])/(x/2))))^2),(((((Sin[(x/2)])/(x/2))))^2)}],{x,-7π,7π},LabelStyle->Medium,AxesLabel->{"sin θ","I"},Ticks->ticks,ImageSize->600,PlotRange->{0,1},PlotStyle->{Thick,{Black,Thin,Dotted}}],
{{α,2.,Dynamic["D = "<>ToString[α]<>"d"]},1.0,10},SaveDefinitions->True]