2
P
ositioning
the
/4
and
/2
Retarder
Plates
Y
ou
can
set
the
state
of
polarization
by
positioning
the
/4,
and
/2
plates
.
1.
Select
a
retarder
plate
.
Y
ou
may
need
to
press
4
Pos
5
rst
to
get
the
display
with
the
plates
.
Press
NNNNNNNNNNN
/4
or
NNNNNNNNNNN
/2
if
the
plate
you
want
is
not
already
selected.
2.
Move
the
plate
to
the
position
you
want.
(See
\Editing"
in
Chapter
1
if
you
need
information
on
changing
the
angles).
Using
the
Circle
Mode
Y
ou
can
set
the
state
of
polarization
by
specifying
the
coordinates
on
the
P
oincare
sphere
.
See
\Setting
the
State
of
P
olarization
"
for
an
explanation.
1.
Select
an
angle
.
Y
ou
may
need
to
press
4
Circle
5
rst
to
get
the
display
with
the
angles
.
Press
NNNNNNNNNN
2 "
B
or
NNNNNNNNNN
2
P
if
the
angle
you
want
is
not
already
selected.
2.
Change
the
angle
to
the
value
you
want.
(See
\Editing"
in
Chapter
1
if
you
need
information
on
changing
the
angles).
Example:
Setting
the
Optimum
Transmission
SoP
T
o
nd
the
state
of
polarization
which
gives
optimum
transmission
for
a
linear
device
under
test
(DUT),
the
steps
are
i.
Set
the
polarizing
lter
.
ii.
Find
the
state
of
polarization
for
worst
case
transmission
(this
is
easier
to
nd,
because
the
resolution
allows
greater
accuracy
at
lower
power).
iii.
Set
the
state
of
polarization
for
optimum
transmission.
F
or
this
example
,
you
will
need,
apart
from
the
polarization
controller
,
a
laser
source
,
and
a
power
meter
(in
the
description
below
,
an
HP
8153A
Multimeter
with
a
laser
module
and
a
sensor
module
are
used).
W
e
will
use
the
length
of
ber
connecting
the
instruments
as
our
linear
DUT
.
1.
With
both
instruments
switched
o,
connect
the
laser
source
to
the
polarization
controller
.
2.
Connect
the
polarization
controller
to
the
power
meter
.
2-4
Setting
a
State
of
P
olarization