Sub-Rayleigh resolution of interference pattern with independent laser   beams
  We propose a new scheme to achieve sub-Rayleigh resolution of interference pattern with independent laser beams. We perform an experimental observation of a double-slit interference with two orthogonally polarized laser beams. The resolution of the interference pattern measured by a two-photon detection is doubled provided the two beams illuminate the double-slit with certain incident angles. The scheme is simple and can be in favor of both high intensity and perfect visibility. 
Jun Xiong, Feng Huang, De-Zhong Cao, Hong-Guo Li, Xu-Juan Sun, and   Kaige Wang