| By managing fiber chromatic dispersion and nonlinearities, the capacity of optical systems has been greatly expanded over the past few years. However, polarization mode dispersion (PMD) and chromatic dispersion slope mismatch in wavelength division multiplexed (WDM) system have recently emerged as one of the critical hurdles in achieving high-performance optical transmission systems.; Many fiber segments deployed throughout the 1980's have a PMD parameter (measured in ps/km1/2) that is as much as 100-1000 times greater than the more-optimized fiber deployed today (<0.5 ps/km 1/2). Therefore, it is highly desirable for ≥10-Gbit/s transmission systems using old embedded fiber to characterize and compensate for signal degradation due to PMD. Previous work on PMD gives a good explanation of the analytical model of PMD, and to some extent, shows their impact on high bit-rate transmission system. Also, several PMD compensation techniques have been proposed to combat the signal degradation due to PMD. Chromatic dispersion management utilizes fiber segments with alternating positive and negative dispersion values so that: (i) an non-zero dispersion always exists throughout the link which keeps nonlinear effects low, and (ii) the net accumulated dispersion remains close to zero at the end of the link to allow high speed transmission. Although dispersion management helps reduce nonlinear effects, remaining residual effects accumulate over long distances and impose a limitation on capacity of WDM systems.; The work presented in this dissertation includes proposing and demonstrating: (i) a technique, PMD locator, which can provide the information of the location, length, and relative magnitude of PMD fiber using stimulated Brillouin scattering, (ii) a adjustable PMD compensation technique using a high birefringence, nonlinearly-chirped fiber Bragg grating (FBG), (iii) that the power penalty distributions of chirped data formats as compared to the power penalty distributions of conventional data formats are less affected by the statistical distribution of PMD, (iv) the realistic PMD emulation technique in short fiber recirculating loop, (v) the simultaneous compensation technique of chromatic dispersion slope mismatch in WDM system using a sampled nonlinearly-chirped FBG. |
