Laser fusion research had been executed on series of Shenguang(SG) high power laser facilities in National Laboratory on High Power Lasers and Physics (NLHPLP) for nearly 50 years in china. Recently, a new high power laser facility with 8 beams laser system and 30kJ/ns/3ωoutput energy has been performed and operated since 2016. Up to now, a multifunction experiment platform including multi-pulse width of ns,ps and fs and active probing beam has been developed. It is becoming a very important experiment platform for Inertial Confinement Fusion (ICF) and High Energy Density (HED).
As an example, the design ideas in a high power laser prototype with four-pass main amplifier and large optical aperture, which has realized the energy output of 15kJ/5ns/1ωin 350mm 350mm clear output aperture, and can output 9.5kJ/5ns/3ω, is introduced. From the system design view, the high amplifier efficiency is considered, and a 3ω damage threshold between 1ω output and final optical aperture is traded off, that is the final aperture is expand by spatial filter, and much more 3ωenergy can be delivered without optical damage in final optical system.
In order to realize the about aims, many new techniques are proposed and developed. we had improved the disk amplifier efficiency about 15% by special design reflector with antioxidant coating, and reduced the ASE in disk amplifier by Sol-gel coating between Nd:glass and cladding. Optical field with amplitude and phase can be simultaneously tested by WCI(Wave -front Code Image) instrument, so much more information can be obtained than near and far field test, and WCI can test the 1ω,2ω and 3ω optical field in the same time at same position, so we can analyze the 3ω beam quality, especial intensity distribution, to improve the damage threshold. The metal sputtering in the final optical structure was eliminated by silica plate on metal support frame also.
In addition, to explore the adaptability of huge high power laser facility with numerous beams for ICF and HED, we give a flexible concept design of geometrical arrangement in the target area to meet the different style experiment requirement.
Jianqiang Zhu is a senior professor of Shanghai Institute of Optics and Fine Mechanics (SIOM), Chinese Academy of Sciences (CAS). He received B.S. degree from Harbin Institute of Technology in 1988, M.S. degree from Changchun Institute of Optics, Fine Mechanics and Physics, CAS in 1990 and Ph.D. degree from SIOM in 1993. He has been working at SIOM since 1993 and served as the director of SIOM from 2001 to 2009. He was also appointed as the director of National Laboratory on High Power Laser and Physics, and serving as the deputy chief engineer of national major projects.
Prof. Zhu has been devoted to the long-term study in the fields of high-power laser system. This includes laser device design, optical engineering, optical beam propagation and control etc. As a chief scientist, he was responsible for several major projects such as Shenguang-II (SG-II) laser facility, SG-II multifunction high-energy laser systems, upgrading SG-II laser device, 3ps petawatt and 30fs multi-petawatt laser facilities, which has contributed immensely to the establishment and development of high-power laser system for ICF study in China. “SG-II multifunction high-energy laser systems” has won the National Science and Technology Progress Award in 2013.
Prof. Zhu has published 320 papers on international journals and holds 50 patents where including 4 patents in USA and Japan. And more than 50 doctoral theses were completed under his supervisor.