Compound motion detection based on OAM interferometry.

The simultaneous and independent measurement of multiple movement forms is a significant issue to be solved in research. In this paper, we proposed a method that combines the self-interference of conjugated optical vortices and external interference of plane waves, and successfully realize the independent measurement of both rotation and rectilinear motion. Three kinds of interference schemes based on vortex beams are analyzed theoretically and verified experimentally. The results show that the double interference between conjugated optical vortices and Gaussian beam can detect the motion along and perpendicular to the beam propagation direction even under complex motion background, providing a powerful way to detect the multiple movement forms of a target. Our work may pave a new way for the detection of spatial noncooperative targets and stimulate the invention of new detection equipment.