All-optical 2R regeneration based on self-phase modulation in the fiber and subsequent offset filtering was investigated numerically and experimentally to restore optical data signals degraded due to amplified spontaneous emission (ASE) noise.Numerical results show that Q factor and amplitude jitter can be improved for 40 Gb/s return-to-zero (RZ) signals with Q factor between 5 and 12 when the fiber input average power is chosen suitably.The regeneration experiment on 10 Gb/s RZ ASE-degraded data signal was demonstrated using a highly-nonlinear dispersion-shifted fiber,and a power penalty of only 0.1 dB was measured at 10-9 bit-error-ratio.