Analysis of optimum avalanche gain of burst-mode receivers for PON applications

We present optimum avalanche gains for burst-mode receivers (BMRx) for passive optical networks (PONs). The avalanche gain is optimized to maximize the geographical coverage of the PON, instead of the BMRx sensitivity. The optimization has been done with respect to differential reach [(DiR) the difference in distance between the longest and shortest optical path] for different splitting factors (SFs). Optimum avalanche gains are calculated for a 1.25-Gb/s BMRx, using both a theoretical model and measurements that take into account the tail occurring after a strong packet, limiting the BMRx dynamic range. The curves that quantify the tradeoff between SF and DiR can be used to select an avalanche gain for gigabit PONs.