Abstract: A passive optical network used to transport traffic signals between a head end and subscriber equipment increases performance and reduces costs while potentially allowing the retention of legacy equipment at the head end and at the subscriber's cable modem. Upstream and downstream traffic signals are converted to upstream and downstream optical wavelengths at customer equipment and head end equipment, respectively, and transported across the PON. The optical signals are converted to electrical signals at the other respective ends, or edges, of the PON, and DOCSIS operation and processing occurs as known in the art. Upstream traffic can be carried at unconventional upstream frequencies. The upper frequency limit of traffic signals is higher than for an HFC, thus providing for potentially more channels, either upstream or downstream.

Abstract: A WDM device separates an information signal and a pump power signal, each having a different wavelength from the other, from a combined signal after the information signal has been amplified by a first fiber amplifier stage. The pump power signal is isolated so that is does not co-propagate with the information signal to another fiber amplifier stage, or from an output of the amplifier assembly. The isolated pump power signal is routed to another WDM device that combines this recycled pump power signal and the information signal provided from the first stage. The recycled pump power is used to stimulate dopant of the next stage fiber amplifier to cause amplification of the information signal above the level provided by the first stage.

Abstract: A fiber amplifier using a single, general-purpose, fixed, gain-flattening filter to provide a flattened response with respect to wavelength for the C-Band. A feedback loop comprises a micro controller that maintains the amplifier in a selected gain-clamped mode. This facilitates use in a variety of networks that may use a variety of different types and brands of equipment. The micro controller varies the bias current of a first laser pump and a second laser pump in response to input received from an input monitor and an output monitor so that the overall selected composite power gain is maintained.