Real-time tracking experiment of higher-order Laguerre-Gaussian beam for remote six-axis deformation sensing

In INSS2008, we described a new principle for monitoring full-axis (three translational and three rotational) deformation of large and long structures such as bridges, roads, and railways. It is based on a combined use of an optical Laguerre-Gaussian (LG) beam and correlation image sensor (CIS). In this paper, we describe theoretically and examine experimentally several key issues of this technology. They are: 1) an optimum design of higher-order LG beam, 2) theoretical analysis on the relation between the beam profile and the deformation parameters, and 3) real-time tracking and parameter extraction algorithms of the LG beam and its parameters.