Getting Started
The Basic Operating Principle
14
Agilent
8169A
Polarization Controller, Second Edition
The Basic Operating Principle
The Agilent 8169A Polarization Controller transforms polarization relative
to a built in linear polarizer.
This means that the optical input is passed through a linear polarizer (Pol),
to extract a single linear polarization.
Figure 1 Block Diagram and Polarization States (non-polarized ! linear polarized)
You should position this plate to get the maximum from the incoming
signal (attach a power meter to the output, and set the angle). The
λ
/4 and
the
λ
/2 plates are then positioned to control the relative state of
polarization of this signal.
Figure 2 Block Diagram and Polarization States (non-polarized ! linear polarized)
You can either set the position of the plates directly, or use the circle
application to set the 2
ε
B
and 2
θ
P
angles that denote the position on the
Poincare Sphere. In addition, using the sphere application, you can vary
the angles of the
λ
/4 and the
λ
/2 plates continuously. By varying the plate
positions slowly, and sampling the response of your Device Under Test,
you can find the maximum and minimum power levels, and thus make
polarization dependent measurements. By varying the plate positions
quickly, and averaging over all the states of polarization, you can measure
the response of your DUT to a “depolarized" signal.
