DMD measurements and equalization Simulations for 62.5- and 50-μm legacy multimode fibers at 1300 nm

We present the results from the differential modal delay (DMD) measurements at 1310 nm performed over a large sample of 62.5- and 50-μm fiber distributed data interface grade multimode fibers (MMF). We have found that the typical DMD values are in the range 0.5-1.5 ps/m, but a significant portion of the measured fibers have DMD values exceeding the commonly used value of 2 ps/m. Since the expected yield at moderate (150-300 m) distances of 10 Gb/s links employing legacy fibers is very poor, we have simulated equalization techniques in the receiver for the measured fiber impulse responses. We show here that both the yield and the achievable distance are improved when equalization is used.