脉宽可调钬激光诱导水下声波信号特性实验研究

800 mm 芯径低氢氧根光纤传输自由运转钬激光脉冲爆炸式汽化光纤端面的水形成汽化泡，汽化泡闭合时会辐射振荡波信号。不同激光参数条件下汽化泡形貌和运动状态有差异，导致辐射振荡声波的个数、强度、谐振周期、声学频率等特性参数不同。为研究不同脉宽对声信号的影响，搭建了声信号测量系统，通过示波器分析计算振荡波声学信号特征参数。结果表明电源电压为1000 V、频率为5 Hz、电源脉宽为0.7~1.6 ms的条件下，随着脉宽增加，声压值整体上先升高但存在多个拐点，达到峰值1.01 MPa后呈现下降趋势，但第一个声学信号频率总体呈下降趋势且最大值为400 Hz。高能量、短脉宽的钬激光脉冲能诱导高强度、多个数、短周期、高频率的振荡波信号。

Abstract

Free-running holmium∶YAG lasers transmitting in a fiber with core diameter of 800 mm can induce vaporization bubble explosively at the end of fiber underwater. Shock waves will be produced upon the vaporization bubble collapse. The shape and dynamic state of vaporization bubble under different laser parameters, can result in variable parameters of the number, intensity, oscillation period, acoustic frequency, and so on, of shock waves. An acoustic measurement system has been built to investigate the influence of pulse duration on acoustic transients, and the characteristic parameters of the first acoustic transient can be recorded by an oscillograph. The experimental results indicate that under the condition of 1000 V voltage, 5 Hz frequency, 0.7~1.6 ms pulse duration of pump power, resonance will happen for the intensity of acoustic transients at the starting period. Finally the intensity will decrease after reaching the peak value of 1.01 MPa. The frequency of acoustic transients will always decrease gradually as the pulse duration of lasers increases, and its peak value can reach 400 Hz. Holmium∶YAG lasers with higher energy and shorter pulse duration can induce acoustic transients with higher intensity, more number, shorter period, and higher frequency.

参考文献

[1] A Vogel, V Venugopalan. Mechanisms of pulsed laser ablation of biological tissues[J]. Chem Rev, 2003, 103(2): 577-644.

[2] R L Blackmon, P B Irby, N M Fried. Comparison of holmium∶YAG and thulium fiber laser lithotripsy: Ablation thresholds, ablation rates, and retropulsion effects[J]. J Biomed Opt, 2011, 16(7): 071403.

[3] H Lee, H W Kang, J M H Teichman, et al.. Urinary calculus fragmentation during Ho∶YAG and Er∶YAG lithotripsy[J]. Lasers Surg Med, 2006, 38(1): 39-51.

[4] M Ith, H Pratisto, H U Staubli, et al.. Side effects of laser therapy on cartilage[J]. Sports Exerc Inj, 1996, 2(4): 207-209.

[5] H Pratisto, M Ith, M Frenz, et al.. Infrared multiwavelength laser system for establishing a surgical delivery path through water[J]. Appl Phy Lett, 1995, 67(14): 1963-1965.

[6] H Pratisto, M Frenz, M Ith, et al.. Combination of fiber-guided pulsed erbium and holmium laser radiation for tissue ablation under water[J]. Appl Opt, 1996, 35(19): 3328-3337.

[7] W Wagner, A Sokolow, R Peartstein, et al.. Thermal vapor bubble and pressure dynamics during infrared laser ablation of tissue[J]. Appl Phys Lett, 2009, 94(1): 013901.

[8] T Lv, Q Xiao, Z J Li, et al.. Influence of water environment on holmium laser ablation performance for hard tissues[J]. App Opt, 2012, 51(13): 2505-2514.

[9] T Lv, Z J Li. Underwater holmium-laser-pulse-induced complete-cavitation bubble movements and acoustic transients[J]. Chinese Sci Bull, 2011, 56(12): 1226-1229.

[10] T Lv, Q Xiao, D Xia, et al.. Cavitation effect of holmium laser pulse applied to ablation of hard tissue underwater[J]. J Biomed Opt, 2010, 15(4): 048002.

[11] M Frenz, G Paltauf, H Schmidt-Kloiber. Laser-generated cavitation in absorbing liquid induced by acoustic diffraction[J]. Phys Rev Lett, 1996, 76(19): 3546-3549.

[12] R Brinkmann, C Hansen, D Mohrenstecher, et al.. Analysis of cavitation dynamics during pulsed laser tissue ablation by optical online monitoring[J]. IEEE J Quantum Electron, 1996, 2(4): 826-835.

[13] E A Brujan, K Nahen, P Schmidt, et al.. Dynamics of laser-induced cavitation bubbles near an elastic boundary[J]. J Fluid Mech, 2001, 433: 251-281.

[14] D Lapotko. Optical excitation and detection of vapor bubbles around plasmonic nanoparticles[J]. Opt Express, 2009, 17(4): 2538-2556.

[15] H W Kang, H Lee, J M H Teichman, et al.. Dependence of calculus retropulsion on pulse duration during Ho:YAG laser lithotripsy [J]. Lasers Surg Med, 2006, 38(8): 762-772.

[16] 吕涛, 肖青, 李正佳. 脉冲钬激光水下空化效应及消融生物硬组织动态特性[J]. 光学学报, 2010, 30(12): 3558-3562.

Lü Tao, Xiao Qing, Li Zhengjia. Cavitation effect of pulsed holmium laser and dynamic characteristics of hard tissue ablation underwater[J]. Acta Optica Sinica, 2010, 30(12): 3558-3562.

[17] M Frenz, F Konz, H Pratisto, et al.. Starting mechanisms and dynamics of bubble formation induced by a Ho∶YAG aluminum garnet laser in water[J]. J Appl Phys, 1998, 84(11): 5905-5912.

[18] M Frenz, G Paltauf, H Schmidt-Kloiber. Laser-generated cavitation in absorbing liquid induced by acoustic diffraction[J]. Phy Rev Lett, 1996, 76(19): 3546-3549.

[19] E D Jansen, T Asshauer, M Frenz, et al.. Effect of pulse duration on bubble formation and laser-induced pressure waves during holmium laser ablation[J]. Lasers Surg Med, 1996, 18(3): 278-293.

[20] 王晓宇, 王江安, 宗思光, 等. 水体深度对激光声信号影响研究[J]. 中国激光, 2013, 40 (11): 1102002.

Wang Xiaoyu, Wang Jiang′an, Zong Siguang, et al.. Research on laser-induced acoustic signals in different water depths[J]. Chinese J Lasers, 2013, 40(11): 1102002.

[21] 李晓龙, 王江安, 宗思光. 基于MEMS膜片的光纤声传感器分析[J]. 中国激光, 2013, 40(10): 1005007.

Li Xiaolong Wang Jiang′an, Zong Siguang. Analysis of optical fiber acoustic transducer with a MEMS membrane[J]. Chinese J Lasers, 2013, 40(10): 1005007.

[22] 王晓宇, 王江安, 宗思光, 等. 水下光击穿的能量分布研究[J]. 中国激光, 2013, 40(10): 1002007.

Wang Xiaoyu, Wang Jiang′an, Zong Siguang, et al.. Research on energy distribution after laser-induced optical breakdown underwater [J] . Chinese J Lasers, 2013, 40(10): 1002007.

吕涛, 张伟, 陈昉. 脉宽可调钬激光诱导水下声波信号特性实验研究[J]. 中国激光, 2015, 42(4): 0404003. Lü Tao, Zhang Wei, Chen Fang. Experimental Research of Acoustic Transients Induced by Holmium: YAG Lasers with Tunable Pulse Duration Underwater[J]. Chinese Journal of Lasers, 2015, 42(4): 0404003.

脉宽可调钬激光诱导水下声波信号特性实验研究

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