Spatial heterodyne readout for optical cavity arrays coupled to neutral atoms

Neutral atoms are a compelling platform for quantum information technologies such as quantum information processing. Optical cavity arrays coupled to neutral-atom tweezer arrays are an emerging technique for enhancing light–matter interactions. Here, we demonstrate a method to read out such cavity arrays by interfering the optical output modes with a tilted reference beam on a camera, constituting a spatial heterodyne. By performing Fourier analysis on the resulting images, we extract the amplitude and phase of each cavity's transmitted field. This readout technique shows promising performance for imaging neutral atom qubits in cavity arrays at low photon counts, even in the presence of significant camera noise.