Experimental test of an alignment-sensing scheme for a gravitational-wave interferometer

Area of Science:

• Optics and photonics
• Interferometry
• Gravitational wave detection

Background:

• Advanced interferometers, like those used for gravitational wave detection, require precise alignment.
• Maintaining alignment in power-recycled Michelson interferometers with Fabry-Perot cavities is critical for sensitivity.
• Existing alignment sensing methods may not cover all degrees of freedom comprehensively.

Purpose of the Study:

• To test a novel alignment-sensing scheme for a power-recycled Michelson interferometer.
• To evaluate the scheme's ability to sense all significant angular degrees of freedom.
• To validate the scheme by comparing measured and theoretical responses to misalignment.

Main Methods:

• A tabletop interferometer simulating a power-recycled Michelson configuration with Fabry-Perot cavities was constructed.
• The alignment-sensing scheme was implemented to monitor angular deviations.
• Misalignment was intentionally introduced across all degrees of freedom.
• The sensor response was recorded for each degree of freedom and compared to theoretical models.

Main Results:

• The alignment-sensing scheme successfully detected misalignment in all tested angular degrees of freedom.
• Measured responses from each sensor showed good agreement with theoretically predicted values.
• The scheme demonstrated robustness in characterizing the interferometer's alignment state.

Conclusions:

• The developed alignment-sensing scheme is effective for power-recycled Michelson interferometers with Fabry-Perot cavities.
• The scheme provides accurate measurements of angular misalignment across all relevant degrees of freedom.
• This technology can contribute to improved stability and sensitivity in precision optical instruments.