Optics Letters, vol.35, no.13, pp.2176-2178, 2010 (SCI-Expanded)
We report the experimental observation of systematically occurring phase singularities in coherent imaging of subRayleigh distanced objects. A theory that relates the observation to the sub-Rayleigh distance is presented and compared with experimental measurements. As a consequence, the limit of resolution with coherent illumination is extended by a factor of 1.64x. © 2010 Optical Society of America.