The time synchronization accuracy of the Shenguang II integrated device in the joint room is 10 ps. If an infrared streak camera is used to assist fine adjustment and control, the synchronization accuracy can also be improved. In April 2000, in the first round of direct drive experiments of the Shenguang II device, the highest neutron yield was 3.9 × 109, which was the highest level of similar devices in the world. The time synchronization accuracy measured at that time was 6 ps.
In laser time measurement, pulsed laser signal-to-noise ratio measurement with distinctive time characteristics is also one of the important parameters of the main laser output. The signal-to-noise ratio of the pulsed laser refers to the energy ratio between the main laser pointer pulse and the previous small pulse (or pre-pulse). It is a parameter to measure the quality of laser pulses. The accuracy of the signal-to-noise ratio measurement mainly depends on accurately interpreting the time position of the noise. The photoconductive switch independently developed by the joint room solves this problem.
The measurement of picosecond laser parameters around the high-energy laser paving tile system is another focus of the work of the measurement and control group. Thanks to the hard work of young researchers and the cooperation with Shanghai Jiaotong University and other units, the measurement and control team has successfully realized the laser parameter measurement of the new field of the beva laser system. Published in important academic journals abroad. In 2016, the measurement result of the signal-to-noise ratio of the tile-waving system 108 was obtained, which made the laboratory’s work in this field reach a world-class level.
The optical path automatic collimation system is an indispensable component of all large high-power green laser pointer devices. Automatic collimation of the optical path of the laser beam is an important part of any laser device that must be run before the target experiment. The design requirements of the laser device for the automatic alignment of the optical path mainly include the index requirements for adjustment accuracy and adjustment time. The adjustment accuracy includes the angle pointing adjustment accuracy of the far field of the beam, that is, the angle shift accuracy, the center translation adjustment accuracy of the beam near field, that is, the translation accuracy, and the beam near-field azimuth rotation adjustment accuracy, that is, the rotation accuracy.
On the Shenguang I device at that time, the optical path debugging of the red laser pointer system mainly relied on manual debugging. The scientific researcher should pass the seed light source output by the laser oscillator along an optical path of hundreds of meters to accurately pass The center finally reaches the target chamber and focuses precisely on the target pill. The workload, required time, and collimation accuracy determined by the human eye cannot meet the experimental requirements of larger devices.