Prescaled 6.3 GHz clock recovery from 50 Gbit/s TDM optical signal with 50 GHz PLL using four-wave mixing in a travelling-wave laser diode optical amplifier

Abstract
Successful 50 GHz operation of a phaselocked loop is demonstrated using four-wave mixing in a travelling-wave laser diode optical amplifier. A prescaled 6.3 GHz clock is recovered from a 50 Gbit/s TDM optical signal using the 50 GHz phase comparison output obtained as the crosscorrelation between a 50 Gbit/s optical signal and a short (< 10 ps) 6.3 GHz optical clock pulse train in the generated four-wave-mixing light.