Balanced optical-microwave phase detector for sub-femtosecond optical-RF synchronization

Area of Science:

• Physics
• Electrical Engineering
• Metrology

Background:

• Accurate timing distribution is crucial for large-scale systems like particle accelerators and telecommunication networks.
• Existing optical-RF synchronization techniques face limitations in achieving sub-femtosecond jitter and long-term stability.

Purpose of the Study:

• To demonstrate the capability of balanced optical-microwave phase detectors (BOMPD) for high-precision optical-RF synchronization.
• To quantify the residual timing jitter and stability performance of BOMPD in large-scale timing distribution.

Main Methods:

• Utilizing balanced optical-microwave phase detectors (BOMPD) for phase comparison and feedback control.
• Implementing robust electronic and optical feedback loops for synchronization.
• Characterizing timing jitter using frequency-domain and time-domain measurements.

Main Results:

• Achieved sub-femtosecond residual timing jitter for optical-RF synchronization.
• Demonstrated long-term stability of < 1 fs RMS and < 7 fs pk-pk drift over 10 hours.
• Measured short-term stability with < 2 fs RMS jitter (1 Hz-200 kHz) and optical-to-RF synchronization at 0.5 fs RMS jitter (1 Hz-20 kHz).
• Attained a noise floor of -161 dBc/Hz, integrating into the sub-femtosecond regime.
• Measured a 50-dB AM-PM suppression ratio with potential for improvement.

Conclusions:

• Balanced optical-microwave phase detectors are highly effective for achieving unprecedented optical-RF synchronization precision.
• The demonstrated performance meets the stringent requirements for next-generation large-scale timing distribution systems.
• BOMPD technology offers a viable path towards sub-femtosecond timing accuracy in demanding scientific and technological applications.