Song Jiao-Jian, Tian Ye, Lu Yuan, Li Ying, Zheng Rong-Er
Guang Pu Xue Yu Guang Pu Fen Xi. 2014 Nov;34(11):3104-8.
With the hope of applying laser induced breakdown spectroscopy (LIBS) to the ocean applications, the laser energy at 532 and 1 064 nm wavelength with 3 and 40 mj respectively was used, which was near their breakdown threshold. Extensive experimental investigations of LIBS from CaCl2 water solution were carried out in this paper using different laser wavelengths of 532 and 1 064 nm. The obtained results show that compared with the 532 nm laser, the 1 064 nm laser can induce the plasma in water with higher emission intensity and longer lifetime, while the reproducibility of LIBS signal under 1 064 nm laser is poorer. On the other hand, due to the different attenuation ratios of 532 and 1 064 nm laser energies in water, the LIBS signal of 1 064 nm laser decreases a lot within the transmission distance range 2-5 cm, while LIBS signal of 532 nm remains the same, because that the wavelength of 532 nm lies in the "transmission window" of the water solution. This study will provide valuable design considerations for the development of LIBS-sea system in near future.
为了将激光诱导击穿光谱技术（LIBS）应用于海洋领域，分别使用了波长为532纳米和1064纳米、能量分别为3毫焦和40毫焦的激光，这接近它们的击穿阈值。本文使用532纳米和1064纳米这两种不同的激光波长，对氯化钙水溶液的LIBS进行了广泛的实验研究。所得结果表明，与532纳米激光相比，1064纳米激光能在水中诱导出具有更高发射强度和更长寿命的等离子体，而1064纳米激光下LIBS信号的重现性较差。另一方面，由于532纳米和1064纳米激光能量在水中的衰减率不同，1064纳米激光的LIBS信号在2至5厘米的传输距离范围内大幅下降，而532纳米的LIBS信号保持不变，因为532纳米的波长位于水溶液的“传输窗口”内。该研究将为在不久的将来开发LIBS-海洋系统提供有价值的设计参考。
