Sampling field sensor with anisotropic fan-out

We describe a new common-path, phase-shift, and shearing interferometric device capable of single-shot detection of optical phase profiles. It samples the input field and uses birefringent plates to fan out phase-shifted copies of the samples in the empty space between them. The phase shifts are given by the thickness of the plates and not by the relative position of the components, as in classical interferometers. This makes the device insensitive to vibrations. We recorded repeatability better than λ/100, even though strong shocks were applied to the air table in proximity to the system. We recorded better than λ/1000 repeatability under quiet conditions and estimated the accuracy to be better than λ/3000 at the shot-noise limit. In addition, the device is compact and easy to integrate in a variety of setups that require the measurement of optical phase profiles.