10
U-CBE, U-CTB
5. After finding the mean value θ, use the conversion table provided with the compensator to find the
retardation. The formula on the next page may also be used to find the retardation.
# If on interference filter is used, use the data on the e-line of the conversion table.
Retardattion (nm) = C ·
│1 / ε
2
–
1 /
ω
2
│
2
│
1–sin
2
θ / ω
2
– 1–sin
2
θ /
ε
2
│
C = Invariables of compensator =
ω,
ε
: Ordinary ray, extraordinary ray refraction
d : Prism thickness of compensator
Shown in
the attached
conversion table.
d ·
ω
1 1
2
ε
2
ω
2
F – line
λ
= 486.1 nm
e – line
λ = 546.1 nm
d – line
λ = 587.6 nm
C – line
λ = 656.3 nm
U-CBE
ω =
ε
=
1.38020
1.39211
1.37859
1.39043
1.37774
1.38954
1.37662
1.38838
U-CTB
ω =
ε
=
1.66820
1.49092
1.66158
1.48762
1.65836
1.48633
1.65437
1.48459