Theodolite with semiconductor laser and polarisation beam splitter for surveying

摘要

The theodolite with a laser light source has a collimating telescope, a focussing lens (10) and a cross wires (12), placed in the collimating telescope, a polarisation beam splitter (13'), placed on the optical axis (O) between the focussing lens and the cross wires and a laser source (16). Light beams from the latter are incident on the beam splitter and reflected from it in the collimation direction. The laser source and cross wires are conjugate with the beam splitter. The laser source is a semiconductor laser that emits linear polarised light.