Model-free precision control of 808 nm laser pulses

We propose a method for precision control of the temporal pulse shape in 808 nm emission from Er-doped fluoroindate glasses. Previously, authors have reported the model based controller design, in which the controller varies and controls the pump rate in real time through the pump power. In model-based design, the performance of the resultant controller depends on the accuracy of the mathematical model used to represent the device in the design process. In this paper a more robust control scheme using model-free approach is presented. Specifically, the controller design is independent of the mathematical model and hence any modeling error has no effect on the device performance. This robustness against modeling error is critical for control purposes in optical materials where various up-conversion parameters are unknown or hard to determine with certainty.