Rapid phase retrieval by lasing

A laser ring system configured to reconstruct an image of an object from an input comprising:

• the object's scattered intensity distribution (SID) and the object's compact support;
• the system comprising:
• two first lenses, one or two second lenses, and at least four beam folding elements, all arranged in a ring configuration of a first- and a second-four-focal telescopes;
• a gain medium, at a first tangent point of the two telescopes, configured to amplify and lase forward beams received from the second telescope towards the first telescope;
• a transmissive spatial light modulator (SLM), at a second tangent point of the two telescopes, configured to selectively lase forward intensity distribution of beams received from the first telescope towards the second telescope, according to their spatial location, wherein the selective lasing is configured to maintain the intensity distributions of the object's SID;
• or
• a reflective spatial light modulator (SLM), at a second tangent point of the two telescopes, configured to selectively reflect intensity distribution of beams received from the first telescope towards the second telescope, according to their spatial location, wherein the selective reflecting is configured to maintain the intensity distributions of the object's SID;
• a spatial intensity binary mask, located between the lenses of the second telescope comprising an aperture in the form of the object's compact support;
• wherein the reconstructed object's image is provided at least at the mask's aperture.