Fault-tolerant and finite-error localization for point emitters within the diffraction limit.

We implement a self-interference technique for determining the separation between two incoherent point sources. This method relies on image inversion interferometry and when used with the appropriate data analytics, it yields an estimate of the separation with finite-error, including the case when the sources overlap completely. The experimental results show that the technique has a good tolerance to noise and misalignment, making it an interesting consideration for high resolution instruments in microscopy or astronomy.