
49-21Polarization Measurement
49.5.1 Measurement of Birefringence
Retardance can be measured using a transmission PSA ellipsometer. A wave plate is a good sample for
th
is
ex
periment
. e re
tardance
δ fo
r
a bi
refringent
sl
ab
of th
ickness
d an
d
pr
incipal
re
fractive
in
dices
n
e
and n
o
is
δ
λ
=
2 d n n( )
e o
(4
9
.43
)
in
th
e
ab
sence
of mu
ltiple
re
ections
. Fo
r
a wa
ve
pl
ate,
th
e
va
lue
of ψ is cl
ose
to 45
°,
an
d
th
e
∆ va
lue
is
eq
ual
to δ. Us
e
a la
mp
so
urce
wi
th
a mo
nochromator
to sc
an
th
e
wa
velength
. Pu
t
a po
larizer
at 45
°
an
d
an an
alyzer
at −4
5°
wi
th
re
spect
to th
e
fa
st
ax
is
of th
e
wa
ve
pl
ate
[4
0]
. Wh
en
λ is sc
anned,
th
e
tr
ansmit-
ted
in
tensity
I th
roug ...