Novel carrier and clock-recovery circuit for multigigabit/second lightwave systems

The first use of a clock pilot-tone to simultaneously recover the carrier and clock signals in a suppressed carrier baseband BPSK optical transmission system was demonstrated. Three signals are obtained from the received pilot-tone, including the reference carrier used to synchronously demodulate the BPSK data, a reference to establish automatic frequency control, and a pattern-independent clock. The pilot-tone method for simultaneous signal extraction was demonstrated for the first time in a baseband multigigabit/second coherent heterodyne detection lightwave system. The recovered clock had a measured rms jitter of less than 1.5 degrees and a spectral width of +or-5 Hz.<>