Experimental results of a semiconductor optical amplifier (SOA) for optical amplification in an IM-DD NOMA-CAP optical access system with a data rate of 50 Gb/s are reported. Specifically, the SOA has been investigated as both booster and pre-amplifier for PON applications. The measured optical power budgets are 28.2 dB and 23.4 dB for the strong and weak NOMA levels, respectively, compared to the budgets for the strong and weak NOMA levels of 12.4 dB and 9.4 dB when no optical amplification is used.