An optical disk (10) includes several tracks (21-23, 121-125) that each include a series of optical data elements (29, 39). Each optical data element includes several reflective surfaces (31-34, 41-44) with respective different orientations that represent stored information. A detection system (210) directs a beam from a laser (217) onto successive optical data elements. The multiple reflective surfaces of each optical data element produce multiple reflected sub-beams that are imaged onto respective portions of a detector (219, 501, 541). The position of each sub-beam on the corresponding portion of the detector is determined, to thereby identify the orientation of the corresponding reflective surface and thus the stored information represented by that surface.