Three-dimensional target monitoring technique based on a morphology correlation for high-power laser applications

Existing monitoring and target positioning systems used in high-power laser fusion experiments have a complex structure and size, making their operation slow and calibration difficult. A simple and accurate positioning technique is proposed here that is based on cross-correlation between the morphology of the target measured at various positions. The morphology of the target is obtained using a spectral interferometer at a video frequency, and its three-dimensional (3D) position is determined by the position of the maximum spatial correlation coefficient. This technique can determine the 3D position and orientation of the target at the sub-micrometer range using only a single compact optical head. The proposed technique is quite simple in its structure and very convenient in operation. The feasibility and performance of the proposed technique is demonstrated in experiments.