Patent ID: 7681453

Claim:
A method to generate and detect ultrasonic surface displacements at a remote target comprising: a. providing a laser ultrasonic inspection system having a generation laser, a detection laser, and an optical sensor; b. providing a multi-mode calibration target having known optical contrast, depth discontinuities, and different shapes; c. calibrating the optical sensor in the laser ultra-sonic inspection system by viewing the calibration target with the optical sensor and comparing and correcting results of the viewing with known information about the multi-mode target; d. generating ultrasonic displacements at a surface of the remote target; e. generating a detection laser beam; directing the detection laser beam to the surface of the remote target; f. scattering the detection laser beam with the ultrasonic surface displacements at the remote target surface to produce phase modulated light; g. collecting the phase modulated light; h. processing the phase modulated light to obtain data representative of the ultrasonic surface displacements at the surface; i. establishing the position of the target using the calibrated optical sensor; and j. correlating the data of step (h) with the position of step (i) so that the surface displacements detected correspond to their location on the target.