POLARIZATION MODE DISPERSION IN OPTICAL COMMUNICATION

Abstract

POLARIZATION MODE DISPERSION MEANS IN THE SIMPLEST CASE THAT AN OPTICAL FIBER EXHIBITS A DIFFERENTIAL GROUP DELAY BETWEEN TWO ORTHOGONAL PRINCIPAL STATES OF POLARIZATION. PMD IS A BIG OBSTACLE FOR HIGH CAPACITY LONG HAUL OPTICAL COMMUNICATION SYSTEMS. ALL TELECOM CARRIERS WITH FIBER PLANTS DATING FROM 1995 OR EARLIER HAVE PROBLEMS TRANSMITTING 40 Gb/S SIGNALS, SOMETIMES EVEN AT 10Gb/S. A STUDY DEMONSTRATING THE EFFECT THAT PMD HAS ON SIGNAL PROPAGATION IN A FIBER AND ON SYSTEM PERFORMANCE HAS BEEN MADE. A 40 Gbps Rz SIGNAL IS LAUNCHED INTO A FIBER SPAN OF 100 Kms.PMD EFFECT IS TURNED ON WITH DIFFERENT PMD COEFFICIENTS, THE FIBER IS SIMULATED AND EFFECT ON THE EYE DIAGRAM & BIT ERROR RATE IS STUDIED. PRACTICAL MEASUREMENT USING WIN-PMD INSTRUMENT AT ORDINANCE CABLE FACTORY HAVE ALSO BEEN DONE. FURTHER PHOTONIC CRYSTAL FIBER HAVE BEEN EXPLORED AS POLARIZATION MAINTAINING FIBER AS THEIR STRUCTURE COULD BE MODIFIED TO INCREASE BIRFRINGENCE. POLARIZATION DIVISION MULTIPLEXING IS AN ALTER...