British researchers develop world's highest gain high power laser amplifier
August 16 04:02:57, 2024
China Instrument Network Instrument Development Researchers at Strathclyde University in the UK have successfully developed the world's highest gain high-power laser amplifiers.
They experimented with the central laser device Vulcan laser system and the Vulcan device was able to output 150 J pulses. In both experiments, the researchers worked closely with the staff of the CLF to adjust the Vulcan so that two different color laser beams could exchange energy in the plasma. The experimentally measured gain coefficient was 180 cm-1. 100 times that of high-power laser system amplifiers based on solid media. Related research results were published in Scientific Reports magazine.
Professor Dino Jaroszynski of the Physics Department of Strathclyde University led the study. He pointed out that the Raman amplification in plasma is a very attractive concept. This concept will win the Nobel Prize for Physics CV Raman The viewpoint is well integrated with plasma, optics, and laser physics. The relatively long high energy laser pulses collide with the short, very low energy pulses in the plasma. There is a beat wave at the point where it collides, as happens when two waves collide. The light pressure of the shock wave drives the plasma to form a regular or trapezoidal shape, while the multilayer ladder acts as a highly reflective, time-varying lens that reflects the energy of the high energy pulse into the low energy pulse, thereby amplifying the low energy pulse and will It is compressed into ultra-short time light pulses. "Our experimental results are very important, because these results demonstrate the flexibility of the plasma medium as an extremely high-gain amplifier medium. The experimental results also show that the efficiency of the amplifier can be great, at least to 10%, which is unprecedented, and There is also a great potential for improvement.
Of course, the current experimental results also show that it is still necessary to further study it in order to achieve a single-stage high-gain and high-efficiency amplifier module. "For example, one of the challenges we still face today is how to deal with the "noise" amplification caused by random plasma fluctuations, which is exacerbated by extremely high gains. This leads to energy losses. Related research is ongoing, I believe that these problems can be well solved in the next experiment."
Dr. Gregory Vieux, who led the research team, pointed out that the plasma is a completely decomposed medium and therefore it has no damage threshold. Therefore, it is possible to amplify short laser pulses without pulse broadening and then compression. Another advantage is that it is theoretically possible to achieve further compression during amplification. This may pave the way for the development of next-generation laser systems. The new generation of laser systems will be able to output ultra-strong and ultra-short pulses, but the cost is only There is a small part of the laser.
"However, we cannot be completely sure that this solution relies on the control of Raman instability. Its growth factor is large, and small plasma fluctuations can cause large instability," said Gregory Vieux.
(Original Title: Britain Develops World's Highest Gain, High Power Laser Amplifier)