Diode-end-pumped all-liquid-cooled square rod Nd: Glass amplifier with sub-joule energy extraction and ultralow thermal induced wavefront. (August 2022)

• Record Type: Journal Article
• Authors: Huang, Wenfa; Guo, Jiangtao; Lu, Xinghua; Wang, Jiangfeng; Fan, Wei; Li, Xuechun; Zhu, Jianqiang
• Is Part Of: Optics & laser technology. Volume 152(2022)
• Publication Date: 2022-08
• Subjects: Laser diode pumped -- All liquid cooled -- Laser amplifier -- Nd:glass -- Thermal effect; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2022.108084
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: A diode-end-pumped all-liquid-cooled square rod Nd: glass eight-pass amplifier is proposed. The total thermally induced wavefront aberration in the Nd: glass square rod is 0.57 µm, which is reduced by 37% compared to the initial structure. Liquid induced wavefront is experimental studied. Abstract: A diode-end-pumped all-liquid-cooled square rod Nd: glass eight-pass amplifier is reported. Amplification energy of 700 mJ under a single-pass small signal gain of 2.36 and input energy of 6.5 mJ at a 1 Hz repetition rate and at 9 J pump energy is achieved, corresponding to an effective energy-extraction efficiency of 25.6%. The total single-pass thermally induced wavefront is measured to be 0.57 μm (peak to valley). To the best of our knowledge, this is the first demonstration of an all-liquid-cooled sub-joule-level square rod Nd: glass amplifier. By optimizing the flowing fluid, the near-field spatial intensity modulation at the maximum energy is 1.38 and 91.6% of the far-field energy is concentrated at three times the diffraction limit.