Theoretical study of all-optical RZ to NRZ format conversion based on cascaded nanoporous silicon waveguides

In this paper, we present that the strong free carrier absorption and short carrier lifetime in nanoporous silicon waveguide can perform effectively the return-to-zero (RZ) to non-return-to zero (NRZ) format conversion. The project presented consisting of two cascaded millimeters long nanoporous silicon waveguides is numerically simulated and investigated at 5 Gbit/s. Numerical results clearly show that the outcome converted signal (NRZ) at the end of proposed device can be effectively optimized (e.g. clearer extinction ratio – ER, higher Q-factor, and lower bit-error rate – BER) by means of suitably choosing the system parameters such as initial RZ peak level and nanoporous silicon waveguide length.