We propose an all-optical modulation formats combination scheme that merges an amplitude-shift keying (ASK) signal and a differential phase-shift keying (DPSK) signal into a single differential phase amplitude-shift keying (DPASK) signal based on parametric amplification in a highly nonlinear fiber. By optimizing the power of the ASK channel, formats combination of ASK and DPSK to DPASK signal is successfully demonstrated by computational simulation. The demodulation process of the generated DPA
