Abstract

The excellent gain, noise, crosstalk and polarization performance of fiber amplifiers assures their benefits in the long-haul network. The additional power splitting capacity that they offer in a passive splitter network, and the consequent sharing of head-end and fiber costs, can provide significant enhancement of PON-based local loop architectures. For cable TV systems, particularly those employing AM-VSB modulation, fiber amplifiers are essential to achieve technical and economic viability, by boosting the limited power budgets. To reduce per customer costs, the head-end and amplifiers must be shared between as many customers as possible. The economics are greatly affected by the choice of modulation format. Using digital modulation, distribution from a final amplifier stage has been demonstrated to 9604 customer terminals, in a broadcast network capable of distributing 384 video channels to 39.5 million terminals. As well as offering such large broadcast capacities and degrees of sharing, digital modulation also avoids the technical problems of analog schemes, such as intermodulation, second-order distortion, RIN, incompatibility with later digital upgrades, etc.

© 1992 Optical Society of America