Versatile All-Optical Clock Recovery Circuit for OOK and DPSK Modulated Data Traffic

We demonstrate the properties of an all-optical processing unit capable of clock-recovery from both OOK and DPSK modulated signals. The circuit is based on periodic sharp filtering and it is suitable for photonic integration. Independently on the modulation format, it is characterised by a tens of MHz locking range, few bits locking time and timing jitter generally below 2% of the bit time. Thanks to these features it can be employed in future optical packet switched networks