Future TBit/s optical communication networks will require a wavelength conversion capability to achieve the additional flexibility to ensure efficient network utilization. Here conversion of data from the 1.3 to the 1.55-mu-m silica fiber loss windows has been demonstrated for the first time using a split-contact semiconductor nonlinear Fabry-Perot optical amplifier. Convesion was achieved by modulating the amplifier gain seen by a 1.55-mu-m CW signal by saturating an absorber section using a modulated 1.31-mu-m signal. Data transfer was possible from 1.31-mu-m to wavelengths between 1.53 and 1.585-mu-m for bit-rates up to 400 MBit/s. The maximum output contrast ratio was 3:1 and the minimum power at 1.31-mu-m required for switching was approximately 60-mu-W. By optically pumping the amplifier to above the lasing threshold using the 1.31-mu-m signal, conversion was obtained to a fixed multiwavelength output with a 10 dB contrast ratio.