7
Example
4
-
Finding
the
P
olarization
Dependence
Example
4
-
Finding
the
P
olarization
Dependence
Function
This
program
does
the
same
thing
as
the
example
session
given
in
chapter
3.
That
is
,
to
measure
the
sensitivity
to
polarization,
by
applying
a
quasi-random
polarization
to
the
(DUT).
Requirements
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).
A
roll
of
ber
will
act
as
a
suitable
DUT
.`
Setting
Up
the
Equipment
1.
With
both
instruments
switched
o,
connect
the
laser
source
to
the
polarization
controller
.
2.
Connect
the
polarization
controller
to
the
power
meter
.
Setup
for
setting
the
position
of
the
polarizing
lter
.
3.
Switch
on
both
instruments
,
and
enable
the
laser
source
.
Note
Under
normal
circumstances
you
should
leave
the
instruments
to
warmup
.
(The
multimeter
needs
around
20
minutes
to
warmup
.)
W
arming
up
is
necessary
for
accuracy
of
the
sensor
,
and
the
output
power
of
the
source
.
Programming
Examples
7-11