a method for imaging and an imaging system , the system includes the steps of : scanning a beam of coherent radiation over a surface along a scan axis ; focusing the beam to a spot on the surface , so that the spot has a predetermined dimension along the scan axis ; spreading the beam laterally while scanning the beam , so that the beam covers an area substantially wider than the predetermined dimension in a direction transverse to the scan axis ; and capturing the radiation scattered from the surface while scanning the beam , so as to form an image of the surface .