General Photonics PDLE-101, Operation Manual

Page: 6 / 61

Section 2. Overview:
The polarization dependent loss (PDL) of a component is defined as the maximum
variation in its insertion loss over all possible polarization states of input light. The PDL
of a system is the vector sum of the PDLs of the components in the system. Since the
relative orientations of the PDL vectors of different parts of a system can change with
temperature or stress on the fiber sections in between, the PDL of a system is a dynamic
phenomenon which can significantly impact the quality of data transmission and
complicate the problem of polarization mode dispersion (PMD) compensation.
Figure 1 Schematic diagram of the changes in the amplitudes of polarization components of a pulse after
propagation through a path with nonzero PDL.
High speed fiber optic transceivers, including those deploying coherent detection
technologies for 40Gb/s and 100Gb/s data transmission, must therefore meet stringent
PDL tolerance specifications.
General Photonics’ PDLE-101 is a PDL emulator specifically designed for PDL tolerance
testing of high speed telecommunication systems. It is available with wavelength
calibrations for either the C or L bands, and can generate discrete PDL values up to 20 dB
with a resolution of 0.1 dB in less than 5 ms. Built-in functions also allow the user to
either sweep or randomize PDL values at user-selectable speeds, enabling the user to
model different types of PDL effects.
The front panel has two adapters to accommodate the optical input and output. The
incoming data stream connects to the light input port of the PDLE. At the output, the
generated PDL is applied to the original data stream.
Document #: GP-UM-PDLE-101-11 Page 6 of 61