Remote six-axis deformation sensing with optical vortex beam

Multi-axis displacement sensing technique with a single optical beam is proposed. Our system consists of propagating optical vortex beam and its imaging system. Since optical vortex beam have feature points known as zero-points or phase singularities in its beam profile, we can detect lateral and rotational displacement of the beam precisely by imaging and tracking the points. Unlike conventional laser displacement sensing techniques, our measurement scheme can be applied for the deformation sensing of civil infrastructures such as bridges and highways where triangulations can not be applied. The basic optical setup is presented and the results of the fundamental experiments are shown.