Laser Wavefront Metrology with Point-source Atom Interferometry

Wavefront aberration is one of the major systematic errors in atom interferometry for precision measurements. Aberrations in the atom optics laser beam result in laser phase shifts that depend on the position of the atom cloud with respect to the aberrations, leading to systematic phase shift errors and to dephasing.

The transverse laser wavefront profile due to aberration can be sampled by an atomic cloud that expands from a point source (point source atom interferometry). Point source atom interferometry establishes a position-velocity correlation, and velocity-dependent phase shifts which encode information about the wavefront are therefore mapped onto a spatial interference pattern. Wavefront aberrations can be characterized by measuring this spatial interference, utilizing imaging techniques including phase-shear read out and leveraging analytical and numerical phase shift calculations we have developed that include higher order phase shift corrections from wavefront aberrations. We will introduce our latest progress in building the initial point-source interferometer apparatus and the implementation of the wavefront metrology protocol.