Wavelength conversions between the two silica fibre loss windows at 1.55 and 1.31 mu m have been demonstrated, for the first time, using difference Frequency generation (DFG) in a periodically domain-inverted LiNbO3 channel waveguide. The conversion efficiency, which is proportional to pump light power, is -31dB for a pump light power of only 3.6mW.