Increasing input power dynamic range of SOA by shifting the transparent wavelength of tunable optical filter

Gain-saturation-induced self-phase modulation (SPM) leading to pulse distor tion in a semiconductor optical amplifier (SOA) is overcome by shifting a t unable optic-at filter (TOF). A recovered or broadened pulse can be obtaine d after filtering the amplified pulse in the SOA even if the short pulse is only 2-3 ps long. The input power dynamic range (IPDR) can be strongly inc reased by shifting the TOF and the direction of the shifted transparent wav elength is different for 10 Gb/s return-to-zero (MZ) or nonreturn-to-zero ( NRZ) signals. The transparent wavelength of the TOF should be shifted to a longer wavelength for RZ signals and to a shorter for NRZ signals. 80-Gb/s optical time division multiplexing (OTDM) signal amplification in the SOA i s demonstrated for the first time. We also demonstrate that a large IPDR fo r the 80-Gb/s OTDM signal can be obtained by shifting the TOF.