Two-bit all-optical analog-to-digital conversion by filtering broadened and split spectrum induced by soliton effect or self-phase modulation in fiber

The Kerr effect in fiber is expected to play a major role in ultrafast all-optical signal processing, which can overcome the obstacles of inherently limited operating speed of electronic devices. In this paper, we propose novel ultrafast and polarization-independent all-optical analog-to-digital conversion schemes. The proposed schemes are realized by filtering the broadened and split spectrum induced by the soliton effect or self-phase modulation in fiber with an arrayed waveguide grating. We conducted proof-of-principle experiments and successfully demonstrated two-bit all-optical analog-to-digital conversions with Gray code output, which shows the feasibility of the proposed scheme.