Table of Contents:

Definition and Overview

1. Introduction to PMD

2. Causes of PMD

3. Associated Effects of PMD

4. Network Impact

5. Potential Solutions

6. The PMD Compensator

7. Compensator's Place in Optical Networks

8. Economic Considerations

Self-Test

Glossary

PDF of this tutorial

Definition
Polarization mode dispersion (PMD) occurs when different planes of light inside a fiber travel at slightly different speeds, making it impossible to transmit data reliably at high speeds.

Overview
PMD is the single biggest challenge facing system vendors and carriers as they attempt to deploy 40 Gbps optical networks. However, PMD is not just a problem at 40 Gbps; it is also evident in 10 Gbps optical networks as well.

This tutorial explains the nature of the PMD problem, what causes PMD, and how to compensate for this problem.