EDFA Design and Analysis for WDM Optical Systems Based on Modal Multiplexing

Adolfo Fernandes Herbster,Murilo Araújo Romero

doi:10.1590/2179-10742017v16i1882

Abstract

Modal multiplexing (MDM) is a core technology to allow a capacity increase in modern optical systems. However, in MDM links, the amplified WDM signal suffers not only from lack of spectral gain equalization but also from unequal modal gain. The proper design of the MDM-EDFA is crucial to provide modal gain equalization and to overcome those impairments, thereby ensuring long haul transmission. In this paper, our methodology of project EDFA design for MDM-WDM systems is presented. The technique is based on a figure of merit arising from the rate and propagation equations which describe the EDFA behavior. This figure of merit is then used for the definition of the objective functions employed in the optimization step, which is based on the non-dominated sorting genetic algorithm NSGA-II. Finally, the method is applied to demonstrate gain equalization through the simulation of a WDM optical system composed of two group modes (LP 01,s and LP 11,s ) with up to 16 channels in each mode. It is demonstrated that, for a MDM-WDM system with optimized EDFAs, the differential spectral gain is the main cause of non-equalization of the amplified signal.

Highlights

There has been an increase on the demand of transmission rate in optical networks, due to novel applications, such as high definition video services (e.g. NetFlix) and data center storage (e.g. DropBox and Google Drive)
That is why recent research has focused on the development of technologies for coherent optical systems based on Spatial-Division Multiplexing (SDM)
The approach is based on a technique presented by us in reference [15], originally for the design of singlechannel FM-EDFAs

Summary

INTRODUCTION

There has been an increase on the demand of transmission rate in optical networks, due to novel applications, such as high definition video services (e.g. NetFlix) and data center storage (e.g. DropBox and Google Drive). The approach is based on a technique presented by us in reference [15], originally for the design of singlechannel FM-EDFAs. in our methodology, the rate and propagation equations are used only as a starting point, to derive a simplified figure of merit, which relates the output characteristics of the FM-EDF to the set of modes composing the input and pump signals. In our methodology, the rate and propagation equations are used only as a starting point, to derive a simplified figure of merit, which relates the output characteristics of the FM-EDF to the set of modes composing the input and pump signals By using this figure of merit, computational effort is greatly reduced, allowing a generalized optimization process to be carried out by means of the non-dominated sorting genetic algorithm II (NSGA-II) [10]. The performance of the designed amplifier is analyzed in the stand-alone form, as well as inserted into the WDM system

PERFORMANCE PARAMETERS

SIMULATION AND ANALYSIS

Findings

CONCLUSION