All-Optical RZ-to-NRZ and NRZ-to-PRZ Format Conversions Based on Delay-Asymmetric Nonlinear Loop Mirror

We perform all-optical return-to-zero (RZ) to nonreturn-to-zero (NRZ) and NRZ to pseudoreturn-to-zero (PRZ) format conversions at tunable bit rates, both by using the same delay-asymmetric nonlinear loop mirror. The temporal and spectral characteristics of the input and output signals are analyzed. Bit-error-rate measurements of RZ-to-NRZ conversion at 10 and 12.5 Gb/s show error-free performance with power penalties less than 3 dB with reference to the input RZ signals.