关键词: 激光放大器/
侧面抽运/
小信号增益/
Nd/
Y:CaF2
English Abstract
Experimental study of diode-pumped Nd, Y:CaF2 amplifier for inertial confinement fusion laser driver
Tang Xiong-Xin1,2,3,Qiu Ji-Si1,2,3,
Fan Zhong-Wei1,2,
Wang Hao-Cheng1,2,
Liu Yue-Liang1,
Liu Hao1,2,
Su Liang-Bi4,5
1.Academy of Opto-Electronics, Chinese Academy of Sciences, Beijing 100094, China;
2.National Engineering Research Center for DPSSL, Beijing 100094, China;
3.Zhongkeheguang Applied Laser Technology Institute Company, Ltd. Tianjin 300304, China;
4.Synthetic Single Crystal Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China;
5.Key Laboratory of Transparent and Opto-functional Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China
Fund Project:Project supported by the Special Fund for Research on National Major Research Instruments and Facilities of the National Natural Science Fundation of China (Grant No. ZDYZ2013-2), the Innovative Talent Promotion Plans for Innovation Team in Priority Fields, China (Grant No. 2014RA4051), and the Youth Innovation Promotion Association, Chinese Academy of Sciences.Received Date:06 May 2016
Accepted Date:31 July 2016
Published Online:05 October 2016
Abstract:In a conventional laser-driven inertial confinement fusion (ICF), Nd-doped phosphate glass is used as a gain medium. However, the repetition frequency operation of such a laser system is restricted by the low thermal conductivity of the phosphate glass. To attain a high ICF performance, the laser driver must be able to operate at a repetition frequency of no less than 10 Hz. Typically, an Nd-doped laser glass operates at a repetition frequency well below 10 Hz. In this paper, an Nd, Y:CaF2 crystal is taken as a gain medium for the laser amplifier, and experiments are carried out to demonstrate the capability of Nd, Y:CaF2 crystal to act as a gain medium for ICF laser driver. A laser-diode plane-array five-direction horizontal-side-pumped Nd, Y:CaF2 laser amplifier 5 mm70 mm is developed and an experimental study is carried out. The absorption spectrum and emission spectrum of Nd, Y:CaF2 crystal and the fluorescence distribution of the amplifier are measured. The Nd:CaF2 co-doped with Y3+ ions results in a broad absorption band, which makes the laser diode pumping more efficient. The strongest excitation band peak is centered around 796 nm. The small signal gains of Nd, Y:CaF2 and Nd:Glass working respectively at repetition frequencies of 10 and 1 Hz under the same pump power are measured. The small signal gain of Nd, Y:CaF2 amplifier reaches 6.12 under a pump power of 9.63 kW, which is 1.5 times that of Nd:Glass amplifier. The measurements of the spectrum of the seed beam and the spectrum from Nd, Y:CaF2 amplifier show that the signals have no change before and after being amplified. Most likely the Nd, Y:CaF2 crystal is a promising laser material for repetitive ICF laser drivers.
Keywords: laser amplifier/
sidepumped/
small signal gain/
Nd/
Y:CaF2
