A multi-beam alignment method is proposed to reduce the total time for aligning at the target area all the laser beams of an ICF laser facility. A number of sub-areas with invariant size and position are extracted from the image acquired by the alignment sensor. An alignment route is comprised of a certain part of those sub-areas, and several alignment routes can cover all the sub-areas. The invariant layout of the sub-areas and the alignment routes is called an invariant sub-area configuration of the alignment sensor. The focused spots of the alignment beams are adjusted in a specific sequence along the alignment routes, and finally reach the desired position on the alignment sensor. The adjustment of all the spots inside each sub-areas is carried out concurrently, and the adjustment along one route for a spot moving from one sub-area into the next sub-area is carried out consecutively. The estimated total time for aligning all the laser beams at target area shows that the proposed multi-beam alignment method has a much higher efficiency.
The target position system (TPS) is one of the important subsystems of an ICF laser facility. However, TPS shows to have kinematic coupling problem in practice. This necessitates iterative adjustment of the Stewart 6-DOF manipulator to make the pose of the target as expected. In every iteration, the pose of the target must be measured, making TPS incompetent in some scenarios which call for only one step to position a target. To handle this problem, this paper proposes a target positioning method focusing on translational kinematic coupling. This method have a significant advantage that it has no relation with both the geometric parameters and the mounting of the target. This makes the proposed positioning method featured by a good practicality. Experiment results show that the proposed method can greatly reduce the position error when positioning a target by only one step.
Array element tiling is one of the key technologies for the coherent beam combination in a high-power laser facility. In this paper, we proposed a method of the array element auto-tiling based on capacitive displacement sensor. The method was verified on a double-pass tiled-grating compressor in XG-III laser facility. The research showed that the method is an effective way to control the misalignment errors automatically, with high precision and long-term stability.