Abstract: A method and apparatus for imaging a scene. The method and apparatus are capable of resolving 3D spatial structure within the scene. The apparatus includes a light source, a timing system and a detector system. The light source emits pulses of light toward the object or target scene being imaged. In one embodiment, the light source is a laser. In another embodiment, the detector system includes an optical system and a monolithic array of light detectors operating in non-linear Geiger-mode. The optical system collects a portion of the light scattered off of objects in the target scene and directs the collected light toward the array of light detectors. In another embodiment, the detector system includes an optical system and a single light detector operating in non-linear Geiger-mode. In this embodiment, the optical system scans the target scene, collects a portion of the light scattered off of objects in the target scene and directs the collected light toward the light detector.