The Phase Encoding Signal Generation Based on the Time Domain Mode Locking Optoelectronic Oscillator

A novel phase-coded microwave frequency comb generation method is proposed and experimentally demonstrated. The system is composed by a time domain mode locking (TDML) optoelectronic oscillator (OEO) and an external injection phase coding signal generator. When the period of the externally injected lower-frequency signal matches the delay time of the OEO loop, the TDML OEO can form a stable oscillation to generate a microwave frequency comb. By applying the phase coding period consistent with the round-trip delay time of the TDML OEO, a phase-coded microwave frequency comb is directly generated. Moreover, the central frequency of the phase coding signal is set to 0 Hz, resulting in the amplitude modulation of the microwave pulses. The magnitude of the phase-coded frequency comb signal is the amplitude modulation pulse signal.