Power Tilt Analysis of Solutions obtained from Multi-objective Optimization of Amplifier Adaptive Control of Operating Point

The definition of the operating point for an optical amplifier is a problem that needs to deal with the characteristics of the amplifier and to return a solution that reaches the best quality of transmission (QoT) for the involved optical link. The definition of the gain needs to be performed autonomously, especially in dynamic optical networks. This problem is called the adaptive control of optical amplifiers operating point (ACOP). One of the most recent ACOP proposal showed that the inclusion of a variable optical attenuator (VOA) in the amplifier output can help to achieve solutions that minimize both the linear and nonlinear interferences in the optical signal. This approach uses a multi-objective optimization algorithm that defines the amplifier gains and VOA losses aiming to maximize the minimum optical signal-to-noise ratio (OSNR) and minimize the OSNR ripple. Nevertheless, another essential aspect for the QoT in the optical system is the signal power tilt, and this metric was not considered in any of the previous ACOP approaches. Therefore, in this work, we analyze the solutions returned by the most recent ACOP approaches to investigate the performance of these solutions concerning the signal power tilt. The obtained results show that solutions with high OSNR and low OSNR ripple can have high power tilt, which indicates that this last metric should be considered in the ACOP approaches.