Ultra-low phase-noise microwave generation using a diode-pumped solid-state laser based frequency comb and a...

Area of Science:

• Photonics
• Laser Physics
• Microwave Engineering

Background:

• Optical frequency combs (OFCs) are crucial for precise frequency generation.
• Achieving ultra-low phase noise in microwave signals derived from OFCs is a significant challenge.
• Existing methods often face limitations in detector performance and noise analysis.

Purpose of the Study:

• To demonstrate ultra-low phase-noise microwave generation at 9.6 GHz using diode-pumped solid-state laser-based OFCs.
• To establish a new phase-noise floor record using commercial photodetectors.
• To optically measure timing jitter and identify phase-noise limitations.

Main Methods:

• Utilized diode-pumped solid-state lasers emitting at telecom wavelengths.
• Employed a common cavity-stabilized continuous-wave laser for referencing.
• Implemented a novel fibered polarization-maintaining pulse interleaver.
• Measured phase noise using commercial PIN InGaAs photodiodes.
• Performed direct optical timing jitter measurement with a balanced optical cross correlator.

Main Results:

• Achieved ultra-low phase-noise microwave generation at a 9.6 GHz carrier frequency.
• Measured a single-oscillator phase-noise floor of -171 dBc/Hz at 10 MHz offset frequency.
• This represents a record for commercial PIN InGaAs photodetectors.
• Identified the origin of phase-noise limitations through direct optical timing jitter measurement.

Conclusions:

• The developed system enables high-performance microwave signal generation from OFCs.
• The novel pulse interleaver and measurement techniques push the boundaries of phase-noise performance.
• Understanding noise origins is key for future advancements in precision microwave generation.