Optical Fiber Telecommunications VIB: Chapter 23. Wavelength-Division-Multiplexed Passive Optical Networks (WDM PONs) (Optics and Photonics)

Wavelength-division-multiplexed passive optical network (WDM PON) has long been considered as an ultimate solution for the future optical access network capable of providing practically unlimited bandwidth to each subscriber. On the other hand, it is still considered to be too expensive for the massive deployment. To solve this problem and meet the ever-increasing demand for bandwidth, there have been numerous efforts to improve the competitiveness of WDM PON. This chapter reviews the current status and future direction of these WDM PON technologies. We first review various colorless light sources, which are critical for the cost-effective implementation of the optical network units (ONUs), and several representative network architectures proposed for WDM PONs. We then review the recent research activities for the realization of high-speed (>10Gb/s) and long-reach WDM PONs. Various fault-monitoring and protection techniques are also reviewed as they can be increasingly important in the future high-capacity WDM PONs.