High-power lasers can produce large amounts of energy, causing some metal to evaporate. In the process of melting, the density of the steel will decrease rapidly and the volume will increase accordingly, and the movement of the material will increase, resulting in high pressure steam. At this time will produce a 'keyhole', it is the blue laser pointer impact point on a narrow hole. The steel around the hole melts to form a pool. After the liquid steel cools, it will connect two sheets of sheet metal. The fundamental cause of most mechanical failures is the presence of defects in the weld, since the weld points are connected to different materials. If the connection is improperly handled, it will eventually cause the stress to be too large. "Improper welding parameters may also cause instability of the welding point, resulting in welds in the pores, part of the penetration or undercut, resulting in the connection is not strong.

Laser measurement and control system is mainly composed of laser parameter measurement, laser optical path automatic collimation and laser control room three subsystems, is an important part of laser driver. All performance indicators and important data for laser drives are available on-line from the laser measurement and control system. The high power laser parametric measurement system is a system that is specifically responsible for laser driver parameter acquisition and measurement. It consists mainly of three measuring branches, namely the energy measurement of the laser beam, the spatial distribution of the laser beam, and the time measurement of the laser beam. The data of these three measurement units are the most important data for a laser system. It is not only an important basis for assessing the working condition, device capability and level of a high-power laser device, but also providing essential physical data for the experiment.

Laser time synchronization (equal to the optical path) measurement, refers to the multi-beam laser synchronization to reach the target time measurement, yellow laser pointer beam target power balance is an important guarantee. According to physical calculations, if the two beam synchronization time difference of 25 ps will lead to 10% power imbalance. And the power balance is extremely important for achieving uniform compression of the target. US LLNL laboratory synchronization accuracy requirements of 10 ps. The time synchronization accuracy of the integrated unit is 10 ps. If the infrared stripe camera is used to assist the fine adjustment and control, the synchronization accuracy can be improved. In April 2000, the highest yield of neutron production was 3.9 × 109, which was the highest level of the same kind of equipment in the first round of the direct drive experiment. The time synchronization accuracy was 6 ps.

Laser energy measurement is one of the most basic elements in laser parameter measurement. It is very important to accurately determine the energy of the target laser to analyze and analyze the experimental data. The research of laser energy measurem