I3COSGRA
Superposition of two cosine waves, one having an optical path differnce δ with respect to the
other. The sum is squared to result in the intensity.
We are looking at the time dependence, the graphs are plots in space x and time t.
Period T, path difference δ , wavelength λ.
1. Graph for optical path difference corresponding to a maximum
λ := 1
N := 15
i := 0 .. N
xi := −.2 + .05⋅ i




A := 1
j := 0 .. N
t1 j := −.2 + .05⋅ j
 δ1  ⋅  cos 2 ⋅ π ⋅  x − t1  − 2⋅ π ⋅  δ1    
  


 2 ⋅ λ     λ T 
 2⋅ λ    
2
uc( x, t1) :=  2 ⋅ A⋅ cos2 ⋅ π ⋅ 
M i , j := uc( xi , t1 j)
M
T≡1
δ1 ≡ 1
t1 ≡ .1
2. Graph for optical path difference corresponding to a minimum.
N := 40
i := 0 .. N
j := 0 .. N
xxi := −.2 + .04⋅ i


t1 j := −.2 + .02⋅ j


 δ2  ⋅  cos 2 ⋅ π ⋅  xx − t1  − 2 ⋅ π ⋅  δ2    
  


 2 ⋅ λ     λ T 
 2⋅ λ    
ud( xx , t1) :=  2 ⋅ A⋅ cos2 ⋅ π ⋅ 
MMi , j := ud( xxi , t1 j)
MM
δ2 ≡ .5
t1 ≡ .1
T≡1
2