The evaluation of phasemeter prototype performance for the space gravitational waves detection

Area of Science:

• Astrophysics
• Gravitational Wave Detection
• Laser Interferometry

Background:

• Future space missions require advanced readout schemes for gravitational wave detection.
• Heterodyne laser interferometry is a leading candidate for detecting subtle phase variances.
• Phasemeters are critical for extracting gravitational wave signals from beat notes.

Purpose of the Study:

• To develop and evaluate a prototype phasemeter for space-based gravitational wave detection.
• To analyze noise sources affecting phasemeter performance.
• To assess the sensitivity and frequency response of the developed phasemeter.

Main Methods:

• Development of a digital phase-locked loop (DPLL) based phasemeter prototype.
• Detailed analysis of noise spectra density sources.
• Experimental evaluation of the phasemeter's sensitivity and performance.

Main Results:

• The phasemeter prototype achieved a sensitivity of 2π μrad/√Hz within the 0.04 Hz-10 Hz frequency range.
• Major noise sources contributing to the noise spectra density were identified and analyzed.
• Thermal drift was observed to increase noise at frequencies below 0.1 mHz.

Conclusions:

• The DPLL-based phasemeter shows promise for future gravitational wave detection missions.
• Understanding and mitigating noise sources, particularly thermal drift, is crucial for improving sensitivity.
• The developed prototype demonstrates a viable approach for precise phase measurement in demanding environments.