A novel centralized light source OCDMA PON without wavelength filters is proposed and experimentally demonstrated.
The OCDMA coded signals and the unmodulated clock pulses are polarization-multiplexed and simultaneously
transmitted in the downlink. Then the received clock pulses at the ONU side are used as the source for the uplink
transmission. The experiment results based on a two-user 2.5 Gb/s OCDMA system show that excellent performance can
be achieved after a 20-km transmission.
A novel upstream data remodulation scheme with downstream ASK-DPSK modulation format is proposed for WDMPONs
in this letter. And this kind of scheme is also experimentally demonstrated on one particular wavelength channel.
Both the 2.5-Gb/s downstream optical DPSK signal and the 2.5-Gb/s downstream optical ASK signal are demodulated
respectively at the receiving side, while part of the downstream carrier is directly remodulated by an optical intensity
modulator for upstream transmission of 2.5-Gb/s data. System performance under different amplitude ratios of
downstream optical ASK signal is investigated. It is shown that effective reception and robust performance can be
achieved after having been transmitted for 25-km.