EDFA for SCM transmission systems

Recently, the application of erbium-doped fiber amplifiers (EDFAs) to access networks with an analogue subcarrier multiplexing (SCM) transmission technique has been investigated. For CATV systems, the EDFAs need to maintain their low noise and distortion characteristics without using high quality but expensive optical components. We examine noise and distortion characteristics of EDFAs with low cost ordinary optical components (e.g. a single-stage isolator with a modest amount of polarisation mode dispersion (PMD), a fused wavelength division multiplexer (WDM) with some polarisation dependent loss (PDL)), which are readily available, and show, for the first time, that EDFAs with optical components of less stringent requirements can be applied to the above mentioned systems without incurring noticeable performance degradation. This study suggests that the mass production of inexpensive EDFAs for AM-CATV access networks is quite feasible.