Optimization of launch conditions in 10-Gb/s links using next-generation multimode fibers

In this letter, we explore the optimization of the intersymbol interference (ISI) penalty and its correlation with various transmitter and fiber parameters characterizing 10-Gb/s 300-m-long local area network links using 50-μm next-generation multimode fibers. The analysis of a large statistical sample suggests that the range of optimal values for the laser encircled flux is 12-16 μm, the lateral offset of the source 10-18 μm, and the axial offset -60 to +60 μm. The optimization of the launch conditions may reduce the ISI penalty by as much as 0.7 dB. The axial offset between the laser and the fiber axes has detrimental effects on the performance of the link if the launch conditions are not optimized.