Synchronized clock multiplication through optical subharmonic injection locking of an optoelectronic oscillator

We propose a remote synchronization scheme based on optoelectronic oscillators (OEO) and external modulators. Synchronized clock multiplication is demonstrated by using optical subharmonic injection locking technique. A 10-GHz slave OEO was successfully synchronized by 2.5-GHz/Gbps injecting optical clock pulse train, return-to-zero (RZ) signal and non-return-to-zero (NRZ) signal, respectively. The synchronization scheme is advantageous since it does not require strong nonlinearity presented in the master signal, and is capable of generating electrical and optical clock with small add-on phase noise.

Research Highlights
► A remote subharmonic synchronization scheme is proposed and demonstrated.
► The scheme is based on the optical subharmonic injection locking of an OEO.
► There is no strong nonlinearity requirement for the injecting master signal.
► Frequency-multiplied electrical and optical clock can be generated simultaneously
► 10-GHz RF clock was obtained from 2.5-GHz/Gbps Clock/RZ/NRZ master optical signal.