Limits on High Bit Rate Wavelength Reuse Using Ultralong Semiconductor Optical Amplifier

Amplitude data erasure for wavelength reuse using an ultralong semiconductor optical amplifier (UL-SOA) in saturation is demonstrated for optical carriers modulated up to 56 Gb/s (NRZ). The erasing performance efficiencies with different input bit rates are presented, as well as the influences of parameters such as input (amplitude) extinction ratio, optical power, wavelength, and UL-SOA bias current. Bit error rate (BER) curves show that the remodulated (upstream) signal has enough quality to be applied in wavelength division multiplexing-passive optical networks (WDM-PON) systems, when very high bit rates or high input extinction ratio are needed and spectral broadening in the erased carrier could be accepted.