Ultra high data-rate optical transmission networks Part 1: Design of an optical system testbed for ultra high speed long haul transmission Part 2: Analysis and Reduction of Polarization Dependent Penalty in Phase Shift keying Demodulators

The thesis consists of two different topics: In part 1, the design of an optical system testbed for long haul transmission using a re-circulating loop, is presented. The testbed operates at 40 Gb/s, it simulates an 1800 km link, with optical amplifiers every 80 km, and 16-32 DWDM channels. The theoretical elements involved in the testbed design are reviewed. The optical components are described and selected. The optical system design parameters are presented as well as design targets and optimization parameters. The final implementation is presented and propagation simulations are performed with RZ/NRZ DPSK, QPSK modulation formats to demonstrate the testbed functionality. In part 2 of the thesis, The BER penalty due to PDf in a DPSK demodulator is analyzed and its effect mitigated. A readily available technique is developed that allows measuring the individual contributions of PDf and PDL on BER and calibrate the demodulator in order to reduce the effective PDf by a factor of two which represents an almost 40% reduction in BER penalty due to PDf. The BER penalty due to PDf is measured for 10- vs. 40-GHz, RZ vs. NRZ DPSK demodulators. Finally, PDf mitigation is demonstrated using a PDL emulator, allowing a 75% reduction in polarization sensitivity.