Sparse light fields in coherent optical metrology [Invited]

In this publication, we demonstrate that recording the mutual intensity, instead of a wavefront, enables interferometric measurements with multiple independent light sources at the same time. This scheme can, for example, be used to overcome the problem of a limited acceptance angle of imaging systems in interferometry. We further show that, for a finite number of light sources, measuring a subspace of the mutual intensity equals the recording of the corresponding light field, which is sparse in phase space. This recording modality offers more flexibility with respect to the trade-off between angular multiplexing and spatial resolution than the state of the art, because it is not restricted by the geometric properties of a microlens array, but rather allows arbitrary sampling of the light field.