A lidar-based 3-D point cloud measuring system and method. An example system includes a base, a housing, a plurality of photon transmitters and photon detectors contained within the housing, a rotary motor that rotates the housing about the base, and a communication component that allows transmission of signals generated by the photon detectors to external components. The rotary component includes a rotary power coupling configured to provide power from an external source to the rotary motor, the photon transmitters, and the photon detectors. In another embodiment, the photon transmitters and detectors of each pair are held in a fixed relationship with each other. In yet another embodiment, a single detector is “shared” among several lasers by focusing several detection regions onto a single detector, or by using a single, large detector.