第 42 卷 第 4 期
2015 年 4 月
Vol. 42, No. 4
April, 2015
中 国 激 光
CHINESE JOURNAL OF LASERS
0404003-
脉宽可调钬激光诱导水下声波信号特性实验研究
吕 涛
1,2,3
张 伟
1
陈 昉
1
1
中国地质大学(武汉)数理学院, 湖北 武汉 430074
2
中国科学院苏州生物医学工程技术研究所江苏省医用光学重点实验室, 江苏 苏州 215163
3
中国地质大学(武汉)地质过程与矿产资源国家重点实验室, 湖北 武汉 430074
摘要 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。
关键词 生物医学光学; 红外脉冲激光; 汽化效应; 脉宽可调
中图分类号 O437 文献标识码 A
doi: 10.3788/CJL201542.0404003
Experimental Research of Acoustic Transients Induced by Holmium:
YAG Lasers with Tunable Pulse Duration Underwater
Lü Tao
1,2,3
Zhang Wei
1
Chen Fang
1
1
School of Mathematics and Physics, China University of Geosciences, Wuhan, Hubei 430074, China
2
Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology,
Chinese Academy of Sciences, Suzhou, Jiangsu 215163, China
3
State Key Laboratory of Geological Processes and Mineral Resource, China University of Geosciences,
Wuhan, Hubei 430074, China
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.
Key words biomedical optics; infrared pulse laser; vaporization effect; tunable pulse duration
OCIS codes 280.5475; 280.3375; 140.3460
收稿日期: 2014-11-27; 收到修改稿日期: 2014-12-19
基金项目: 武汉市青年科技晨光计划(201271031430)、中国博士后科学基金面上项目(2014M2104)、中国科学院江苏省医用
光学重点实验室开放基金(JKLMO201405)、湖北省自然科学基金(2014CFB335)
作者简介: 吕 涛(1977—),男,博士,副教授,主要从事激光医学方面的研究。E-mail: lvtaohn@sina.com
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