Long-term stable microwave signal extraction from mode-locked lasers

Area of Science:

• Optical Engineering
• Microwave Engineering
• Laser Physics

Background:

• Mode-locked fiber lasers are crucial for generating stable optical and microwave signals.
• Precise synchronization of high-frequency microwave signals is essential for advanced scientific and technological applications.
• Existing methods face challenges in achieving long-term phase stability at high frequencies.

Purpose of the Study:

• To demonstrate long-term synchronization of 10.225 GHz microwave signals.
• To achieve high phase stability for microwave signals extracted from a passively mode-locked fiber laser.
• To establish a new benchmark for microwave signal stability using photonic techniques.

Main Methods:

• Utilized balanced optical-microwave phase detectors for signal synchronization.
• Locked two 10.225 GHz microwave signals to a 44.26 MHz repetition rate passively mode-locked fiber laser.
• Performed out-of-loop measurements for timing jitter and long-term drift analysis.

Main Results:

• Achieved 12.8 fs relative timing jitter integrated from 10 Hz to 10 MHz.
• Demonstrated a maximum timing drift of 48 fs over one hour.
• Reported 3 mrad-level phase stability for the 10.225 GHz microwave signal over extended periods (>1 hour).

Conclusions:

• Successfully demonstrated robust long-term synchronization of high-frequency microwave signals from a mode-locked fiber laser.
• The achieved timing jitter and phase stability represent a significant advancement in precision microwave signal generation.
• This work paves the way for improved performance in applications requiring highly stable microwave signals.