Abstract: The plurality of emitters and the plurality of detectors form a light curtain that is patterned about the beam, and are positioned to surround the beam. The plurality of emitters each have a centerline and each have a divergence angle centered on the centerline. The placement and orientation of the plurality of emitters about the acceptance centerline of the beam receiver are configured to align the centerlines of the plurality of emitters substantially parallel to the incoming beam. The detection of one or more of the plurality of emitters by one or more of the plurality of detectors depends on the divergence angles of each of the plurality of emitters and the tilt of the beam receiver relative to the beam centerline.

Abstract: The present disclosure is directed toward a beam projection system, including a beam transmitter, a beam receiver, a plurality of emitters, and a plurality of detectors. The beam transmitter has one or more light sources to transmit a beam, and also has a centerline. The beam receiver is arranged to receive the beam from the beam transmitter. The beam receiver has an acceptance centerline. The plurality of emitters and the plurality of detectors form a light curtain that is patterned about the beam, and are positioned to surround the beam. The plurality of emitters each have a centerline and each have a divergence angle centered on the centerline. The placement and orientation of the plurality of emitters about the acceptance centerline of the beam receiver are configured to align the centerlines of the plurality of emitters substantially parallel to the incoming beam.