ON LINEAR CONTROL OF BACKWARD PUMPED RAMAN AMPLIFIERS.

This paper considers the modelling and control of a particular type of optical amplifier that finds application in long-haul wavelength division multiplexed optical communications systems. The objective of this consideration is to design and demonstrate a simple (and potentially cheap) linear control strategy for regulating amplifier output signal power across a range of signal wavelengths in the presence of upstream signal power uncertainty, where limited control authority is available. Although such amplifiers are highly nonlinear and distributed devices, the straight-forward application of linearization, model reduction and ℋ∞ loopshaping design is demonstrated to be a promising approach for achieving the stated amplifier control objectives.