Abstract: An optical access network system can be used to upgrade legacy passive optical networks by subdividing currently used optical bands (e.g., C-, S-, or O-bands) into subbands to support more wavelengths. The subbands can be used to provide various current or emerging services to end users. Optical transmitters may selectively transmit modulated/unmodulated optical signals in multiple subbands downstream. Demultiplexers demultiplex the optical signals into respective bands and subbands for delivery to multiple respective destinations. Optical transceivers may receive and modulate downstream, unmodulated, optical signals (e.g., in the optical O-band) and transmit the modulated optical signals upstream. Upgrades to legacy systems or future systems can be implemented in a cost effective manner with negligible, if any, disruptions in service noticed by the end user.

Abstract: In one aspect of the invention, a control system for use in an optical amplifier includes a plurality of control legs, each operable to receive one of plurality of portions of an optical signal, wherein each of the plurality of portions comprises a different percentage of the optical signal. The system further includes a plurality of registers, each associated with one of the control legs and each operable to store a value proportional to the portion of the optical signal communicated in the associated control leg. The system also includes a controller operable to select one of the values stored in one of the plurality of registers and to scale that value by a scaling factor to generate a scaled value, wherein the scaling factor is determined at least in part by the percentage of the optical signal associated with that value. The controller is operable to generate, based at least in part on the scaled value, a control signal operable to affect the gain of the amplifier.