中国激光, 2018, 45 (2): 0207029, 网络出版: 2018-02-28
纳秒激光在水和金纳米球溶液中的光致击穿研究 下载: 885次
Research of Optical Breakdown Induced by Nanosecond Laser in Water and Gold Nanosphere Solutions
激光技术 光致击穿 散射光检测 金纳米球 laser technique optical breakdown light scattering detection technique gold nanosphere
摘要
利用等离子体成像、散射光检测技术综合研究了聚焦的纳秒激光在去离子水和24 nm粒径的金纳米球溶液中的光致击穿现象。随着激光能量的增加,强击穿过程中产生的明亮等离子体区域增大,且沿轴向逐渐产生多个明亮等离子体区域,即多点击穿;同时,产生的明亮等离子体区域沿光轴方向的延伸具有不对称性,低浓度的金纳米球溶液中更加明显。弱击穿通常只发生在激光能量比较低的情况中,激光能量到达一定阈值时,只出现强击穿。低浓度的金纳米球溶液能显著降低光致击穿所需的最低能量;而金纳米球浓度增加,光致击穿所需能量增加。与去离子水中相比,金纳米球溶液中的光致击穿更容易获得亚微米尺度的空化气泡,且产生的空泡尺寸更加稳定。
Abstract
Optical breakdown induced by nanosecond laser in deionized water and gold nanosphere solutions with 24 nm diameter is investigated based on bright plasma imaging and light scattering detection technique. More than one laser-induced breakdown regions are generated along the direction of beam propagation as a function of incident laser energy, which is denoted as multi-point breakdown. And the stretching of bright plasma is asymmetry along optical axial direction, especially in low concentration of gold nanoshere solution. Weak breakdown occurs only when laser energy is low, and strong breakdown occurs only when laser pulses energy exceeds the given energy. Low concentration gold nanosphere can decrease the minimum energy which could induce optical breakdown by laser pulses. Increasing concentration of gold nanosphere can lead to the larger energy threshold of optical breakdown. In addition, it′s easier to get submicron size bubble in gold nanosphere solutions than in deionized water, and the size of bubble induced in gold nanosphere solutions are more stable.
付磊, 王思琪, 辛静, 张镇西, 王晶. 纳秒激光在水和金纳米球溶液中的光致击穿研究[J]. 中国激光, 2018, 45(2): 0207029. Fu Lei, Wang Siqi, Xin Jing, Zhang Zhenxi, Wang Jing. Research of Optical Breakdown Induced by Nanosecond Laser in Water and Gold Nanosphere Solutions[J]. Chinese Journal of Lasers, 2018, 45(2): 0207029.