Suppression of third-order dispersion and sideband instability in ultra-long-haul ultra-high-speed optical fiber transmission using midway optical phase conjugation

Abstract

In this dissertation, the performance improvement of the optical phase conjugation (OPC) systems by suppressing the third-order dispersion (TOD) and the sideband instability (SI) is studied. For the TOD compensation, we predict that the accumulation of TOD in OPC systems is almost linear. We demonstrate the possibility of a 100-Gbit/s data transmission over 10,000 km by only performing the TOD compensation. For the SI suppression, we derive the complete theoretical analysis of the SI that occurs when two fibers with different characteristics are concatenated to form a dispersion-managed fiber link. We find that the magnitude of the SI gain reduces with the increase in the strength of dispersion management. Since the strong dispersion management link using the combination of a standard single-mode fiber (SMF) and a reverse dispersion fiber (RDF) can realize the simultaneous compensation of the second-order dispersion (SOD) and the TOD, we employ this combination of SMF and RDF to simultaneously suppress both TOD and SI in OPC systems. By computer simulation, we demonstrate the possibility of a 200-Gbit/s data transmission over 10,000 km by only optimizing the dispersion map and the input signal power. For alternative method for compensation of SI, we propose the use of distributed Raman amplification (DRA) to construct a reverse power distribution in the second half of OPC systems, in order to form the entirely symmetrical distribution of signal power with respect to the system midpoint. The result of our simulation also shows that the 200-Gbit/s data can successfully transmit over 10,000 km. For computing pulse propagation in optical fiber, we develop several algorithms based on the finite-difference time-domain (FDTD) method. The results of the simulations are compared with the results obtained from the split-step Fourier method (SSFM), which is the common method used for calculating signal propagation in optical fibers. Our developed FDTD algorithms show a possibility of the calculation over several ten kilometers with acceptable accuracy.