COUPLING OF VCSEL ARRAY VIA MULTIMODE FIBER FOR COAXIAL ILLUMINATION IN TRACKER SYSTEM

A surveying instrument for surveying a scene including a target is provided. The surveying instrument comprises a front lens comprising an optical axis, and a multimode fiber comprising a core. The surveying instrument comprises a transmitter arrangement comprising a two dimensional array of vertical cavity surface emitting lasers (VCSELs). A first end of the multimode fiber is arranged to receive at least a portion of a light beam emitted by the transmitter arrangement for illuminating a major part of the core of the multimode fiber. A second end of the multimode fiber is arranged at the front lens for transmitting a beam coincident with the optical axis towards the scene including the target. The surveying instrument comprises a receiver configured to receive light reflected at the target via an optical path separate from the multimode fiber. The optical path includes the front lens, and the optical path coincides with the optical axis at the front lens.