Criteria for optimizing laser launch conditions in 10 Gb/s links using OM3 fibers

In this paper we present the dependence of the ISI penalty and ISI failure rate on various transmitter and fiber parameters characterizing 10 Gb/s Ethernet links with 300 m long OM3 multimode fibers operated at 850 nm. Statistical optimization of the launch conditions results in optimal values for the laser encircled flux (13–17 μm) and lateral offset of the source (10–18 μm). The analysis of the ISI failure rate and ISI correlation coefficients showed that without additional optimization, the axial offset between the laser and the fiber axes has detrimental effects on the performance of the TIA-compliant links and it should be less than 60 μm. The optimization of the launch conditions with additional criteria going beyond TIA requirements may reduce the ISI penalty by as much as 0.7 dB leading to ISI penalty well below its allocation limit of 2.5 dB. This gives an opportunity to increased link lengths beyond standardized 300 m.