Wavefront Mapping for Absolute Atom Interferometry

Area of Science:

• Atomic physics
• Quantum optics
• Metrology

Background:

• Wavefront distortions in light-pulse atom interferometry introduce systematic uncertainty.
• Current limitations in measuring gravitational acceleration are at the 30 nm/s² level due to these distortions.

Purpose of the Study:

• To develop and demonstrate an in situ method for spatially resolving interferometer phase.
• To characterize and correct wavefront bias in Mach-Zehnder atom interferometers.
• To improve the precision of absolute gravitational acceleration measurements.

Main Methods:

• Utilized a Mach-Zehnder atom interferometer.
• Introduced controllable curvature to the Raman light using an adjustable collimation retro-reflector.
• Spatially resolved the interferometer phase to measure wavefront bias.

Main Results:

• Demonstrated measurement of bias due to parabolic wavefront curvature with 1 mrad uncertainty.
• Showed that finite-size corrections influence the measured phase curvature.
• Quantified the impact of wavefront distortions on atom interferometer measurements.

Conclusions:

• The developed measurement process can characterize and correct wavefront bias.
• This technique can reduce wavefront bias uncertainty below the nm/s² level in optimized atom interferometer gravimeters.
• Enables higher precision in absolute measurements of gravitational acceleration.