The agilent 8169a polarization controller, Page 3 of 6 – Atec Agilent-8169A User Manual
Page 3
 
Page 3 of 6
The Agilent 8169A Polarization 
Controller 
 
The Agilent 8169A provides polarization synthesis 
relative to a built-in linear polarizer. The quarter-
wave plate and half-wave plate are individually 
adjusted to create all possible states of 
polarization. Pre-deterministic algorithms within 
the Agilent 8169A enable the transition path from 
one state of polarization on the Poincare
1
sphere
to another to be specified along orthogonal great 
circles. These features are important because 
device response data can be correlated to specific 
states of polarization input to the test device. 
 
PDL measurement of DWDM components using 
Mueller method is one of the main applications. 
The Mueller method stimulates the test path with 
four precisely known states. Precise measurement 
of the corresponding output intensities allows 
calculation of the upper row of the Mueller matrix, 
from which PDL is in turn calculated. This method 
is fast, and ideal for swept wavelength testing of 
PDL. 
 
Figure 2: Orthogonal circles on the Poincare 
sphere
1
show how the Agilent 8169A synthesizes
relative state-of-polarization points according to a 
specified path. 
 
Figure 3: Agilent 8169A block diagram 
 
_______ 
1
The Poincare Sphere is a three-dimensional
graphing system for viewing all possible states of 
polarization. 
Linear
λ/4
λ /2
Polarizer plate plate
Optical
Input
Optical
Output