Network-embedded self-tuning cavity for WDM-PON transmitter

A network-embedded self-tuning cavity is proved in wavelength division multiplexed passive optical network transmission over 32 channels. The external source-less topology takes advantage of a reflective element at the remote node and a reflective semiconductor optical amplifier at the optical network unit to establish a distribution-fiber based cavity. The bit error rate performance of up to 5-km cavities is presented with two optical network units simultaneously operating and with downstream signal co presence. The experimental analysis at 1.25 Gb/s provides an evaluation of polarization dependences when exploiting low polarization dependent gain reflective semiconductor optical amplifiers with 25-km and 50-km standard single mode fiber transmission.