摘要
理论上分析了脉冲激光在液体中产生的声波波阵面随光声源形状的变化,以及不同激发机制下光声脉冲波形的差别,并从实验中得出了脉冲CO2激光光声脉冲频谱特性。结果表明光声波波阵面为球面或柱面,热弹机制激发双极性的光声脉冲,汽化机制激发单极性的光声脉冲, CO2脉冲激光在水中激发的声波频谱峰值主要在100 kHz以下。通过选择光声源的形状和激发机制可以获得所需的光声信号。
To get the characteristics of laser acoustics, the relationship between the shape of the wave front and the shape of laser-acoustic source, the difference of waveforrn of the laser acoustic pulse excited in different mechanisms were analyzed theoretically. The frequency characteristic of laser sound induced by pulsed CO2 laser was acquired experimentally. The re suits showed that the acoustic wave front was spherical or cylinder, the bipolar acoustic pulse was induced thermoelastically and the single polar wave was induced by vaporization. Frequency spectrum peak of acoustic wave induced by CO2 laser in water is under 100 kHz. Required laser acoustic signal could be obtained by choosing shape of the source or inducing mecha nism of laser sound.
出处
《光学与光电技术》
2006年第3期28-31,共4页
Optics & Optoelectronic Technology
基金
武汉理工大学校基金资助课题(XJJ2004111)
关键词
光声效应
脉冲激光
热弹机制
汽化
介质击穿
photoacoustic effect
pulse laser
thermoelastic mechanism
vaporization
dielectric breakdown
