脉宽可调钬激光诱导高速射流实验研究  

Experimental Study of Tunable Pulse Duration Ho∶YAG Laser-Induced Liquid Jet

作　　者：吕涛[1,2,3] 张伟[1] 陈昉[1] 

机构地区：[1]中国地质大学(武汉)数学与物理学院,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

出　　处：《中国激光》2015年第7期124-131,共8页Chinese Journal of Lasers

基　　金：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)

摘　　要：光纤传输红外脉冲激光在密闭容器内爆炸式汽化液体形成汽化泡促使液体体积急剧膨胀,在喷嘴处形成高速液体射流。利用聚偏氟乙烯（PVDF）针式水听器探测不同激光参数和光纤位置条件下钬激光脉冲诱导高速液体射流的射流压力和汽化效应诱导声波信号,其电信号在示波器上显示并记录,分析射流压力和声波强度与激光脉宽和激光强度的变化关系。实验结果表明激光平均能量为426.3 mJ时射流压力与脉宽（494～967μs）呈正相关函数变化关系,声波强度在光纤末端与喷嘴间距d=2 cm和d=4 cm时与脉宽呈负相关函数变化关系,d=6 cm时声波强度随脉宽的增大呈先升后降的变化趋势,在736μs脉宽时声波强度达到最大值1.32 MPa;脉宽为480μs时射流压力和声波强度随激光能量（266.3～420.8 mJ）增大而增大;当激光参数恒定时声波信号和射流信号均随d增大而增大。High speed liquid jet from the nozzle of one closed vessel can be formed, which is urged by vaporization effect induced by fiber- transmitting infrared pulse lasers. The signals of water- jet pressure and shock wave pressure under various laser parameters and stand-off distances（d： distance between the end of optical fiber and the nozzle exit） are detected by two polyvinylidene fluoride（PVDF） needle hydrophones and are recorded by one oscilloscope. The relationship between water-jet pressure, shock wave pressure and pulse duration, laser energy is analyzed. The experimental result indicates that there is a positive correlation between water-jet pressure and pulse duration（494～967 μs） when the laser energy is 426.3 mJ. Contrarily, the relationship between shock wave pressure and pulse duration is negative when d is 2 cm or 4 cm. However, for d=6 cm the shock wave pressure increases firstly and decreases afterwards, and reaches a maximum value of 1.32 MPa when the pulse duration is736 μs. Both water jet pressure and shock wave pressure increase in proportion to pulse energy（266.3～420.8 mJ）when the pulse duration is 480 μs. When the laser parameters are invariable, jet pressure and shock wave pressure all increase with increase of d.

关 键 词：医用光学 脉冲钬激光 汽化泡 高速射流 

分 类 号：O437[机械工程—光学工程]