PSY-201 User Guide
GP-UM-PSY-201-11
Page 7 of 105
Section 1.0
Overview
The PSY-201 Polarization Synthesizer/Analyzer combines General Photonics’ PolaDetect™
(POD-201) high speed in-line polarimeter and PolaRite™ III polarization controller with reset-free,
proprietary polarization control algorithms to achieve a wide range of polarization control
functionalities: the ability to generate and maintain any desired state of polarization (SOP),
regardless of the input SOP; real-time SOP and DOP monitoring; generating special SOP points,
sequences, and traces; polarization scrambling and modulation. It is packaged in a 2U-height,
half-rack size enclosure, as shown in Figure 1. The all-fiber construction polarization controller
provides very wide operation bandwidth with extremely low insertion loss, polarization dependent
loss, and activation loss. Applications include real-time polarization measurement and control,
transceiver polarization testing, passive/active component characterization, interferometry, optical
remote sensing, RF photonics, and other polarization sensitive applications.
Figure 1 PSY-201 polarization synthesizer/analyzer
1.1 Principle of Operation
A polarization controller can be constructed from either a series of rotatable fixed-
retardation plates or a series of variable retardation plates of fixed orientation. An example of the
latter scheme, using four variable retardation wave plates, is shown below, in Figure 2a. Figure 2b
shows a fiber-based version of this design, which consists of four piezoelectric actuator-driven
fiber squeezers oriented 45° from each other. Each fiber squeezer is driven by an applied voltage
signal. Squeezing the optical fiber produces a linear birefringence in the fiber, and thus, alters the
state of polarization of a light signal passing through it.
