We propose a 6-mode-group ring core multimode erbium doped fiber amplifier (RC-MM-EDFA) capable of providing almost identical gain among the six mode groups within the C band using either core-or cladding-pumped implementations. IntroductionSpace Division Multiplexing (SDM) has attracted considerable attention in the fiber-optic community as a radical approach to increase the per-fiber capacity by employing multiple distinguishable spatial information channels through the same glass strand

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In this study a component map generation method which can identify component characteristics conversely from limited performance deck data provided by engine supplier was newly proposed using a hybrid method with the genetic algorithms and the system identification method. Generally component performance characteristics of compressor and turbine can be expressed as the third order equation with the related function of the engine rotational speed versus the pressure ratio, the mass flow function and the isentropic efficiency. According to the newly proposed scheme, firstly the scaling is performed at each engine rotational speed with some limited performance data which are provided by engine manufacturer, and then the component characteristic equations are obtained using system identification method. Then the initially obtained component characteristics are modified by considering engine component behavior for various operational conditions such as flight Mach number, altitude and atmospheric temperature using genetic algorithms. In the modification, the component characteristics obtained by system identification are used as initial data to reduce the calculation time. And finally component maps are generated by integrating the component characteristic equations taken at each engine rotational speed. In order to verify the proposed method, steady-state performance analysis using the newly generated component maps were performed, and the analysis results were compared with the performance deck data and the analysis results using the traditional scaling method. In this investigation, it was found that the newly proposed map generation method (1% errors) is more effective than the traditional scaling method (10% errors) in overall operational region.

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