High-resolution characterization of parametric sampling based photonic phase locking

We demonstrate a novel photonic phase locking between the pulse train from a passively mode locked laser and the photonic signal generated from an actively mode locked laser. A high-resolution characterization of the photonic phase locking is also presented. In the phase locking loop, the phase detection is employed by the parametric sampling in a photonic crystal fiber and its residual error is characterized by both the phase noise measurement and the digitization of the sampling results. The residual phase noise measurement derives an integral timing jitter of 1.7 fs and the digitization reaches an 8-bit resolution at 220 GHz carrier, which verify the good performance of the phase locking loop.