RSOA Intensity Modulator Frequency Chirp-Enhanced Optical OFDM PON Performance

A reflective semiconductor optical amplifier intensity modulator (RSOA-IM) frequency chirp considerably increases the system frequency response of an intensity-modulation and direct-detection (IMDD) PON system over the passband signal spectral region. Adaptive bit and power loading of optical OFDM (OOFDM) enables full use of the RSOA-IM frequency chirp-enhanced passband system frequency response characteristics. As a direct result, without requiring extra electrical and optical equalization schemes, an RSOA-IM with a 3-dB small-signal modulation bandwidth as low as 1 GHz can support 40 Gb/s OOFDM signal transmissions over 25 km SSMF IMDD PON systems free from optical amplification and chromatic dispersion compensation. This paper suggests that significantly relaxed requirements on both RSOA-IM's 3-dB small-signal modulation bandwidth and frequency chirp are feasible for achieving desired OOFDM transmission performances for next-generation PONs.