DML and ILO based clock recovery scheme for burst-mode 4-PAM optical data transmission in PON

A clock-recovery scheme is proposed for the burst-mode optical data transmission using 4-level pulse-amplitude modulation in passive optical networks. It utilizes the nonlinear relaxation oscillation from a directly modulated laser to generate a clock tone at the transmitter. At the receiver side, it employs an injection locked oscillator (ILO) to lock to the clock tone and generates a full clock. A band-pass-filter is inserted before the ILO to reduce the jitter in the generated clock.