The first images from optical aperture synthesis

The attainment of diffraction-limited images with large ground-based optical telescopes is an important objective for many astronomical programmes. The limited resolution set by atmospheric fluctuations in refractive index can be overcome by applying aperture synthesis and phase-closure techniques to short-exposure images taken through non-redundant aperture masks. The first optical images obtained with this technique are presented here. The diffraction limit is achieved with good dynamic range even when the number of photons in each short exposure is small (<<100).