title: Measurement of PMD tolerance in 40-Gb/s polarization-multiplexed RZ-DQPSK.
abstract: We experimentally investigate the first-order polarization-mode dispersion (PMD) tolerance of two polarization-multiplexed (POLMUX) RZ-DQPSK signals at overall 40 Gb/s. The polarization demultiplexing is enabled by an automatic endless polarization stabilizer. Time-interleaving the two orthogonally polarized RZ-DQPSK signals minimizes the crosstalk due to the non-ideal polarization stabilization, while it represents the worstcase for the PMD-induced crosstalk. Bit-error rate measurements are performed both in back-to-back and after 25-km standard single-mode fiber. The PMD tolerance is evaluated as a function of the instantaneous differential group delay, introduced by a first-order PMD emulator. 40-Gb/s POLMUX RZ-DQPSK is more sensitive to PMD than single-polarization 20-Gb/s DQPSK, while it is more PMD-tolerant than 40-Gb/s NRZ-OOK. Besides, its chromatic dispersion robustness is similar to the single-polarization 20-Gb/s DQPSK. The combination of POLMUX and DQPSK is therefore very promising in view of transmission systems at high bit-rate.
authors: Department of Electronics and Information, Politecnico di Milano, Via G Ponzio 34/5, 20133 Milan, Italy.
authors: Pierpaolo
authors: P
authors: Boffi
authors: Maddalena
authors: M
authors: Ferrario
authors: Lucia
authors: L
authors: Marazzi
authors: Paolo
authors: P
authors: Martelli
authors: Paola
authors: P
authors: Parolari
authors: Aldo
authors: A
authors: Righetti
authors: Rocco
authors: R
authors: Siano
authors: Mario
authors: M
authors: Martinelli
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*