In this letter, for the first time, a novel 100G pre-amplified self-coherent passive optical network (SC-PON) architecture is proposed and experimentally verified. To mitigate the reduction in receiver sensitivity resulting from co-transmitted carriers in self-coherent systems, a semiconductor optical amplifier (SOA) was deployed for pre-amplification with a noise figure of 7.5dB and a small-signal gain of 30dB. As a proof-of-concept, a system experiment of pre-amplified 25-GBaud 16-QAM SC-PON is demonstrated in the downstream, achieving a data rate of 100 Gb/s/ $lambda $