衍射法测量低频液体表面波的衰减系数  

Measurement of the attenuation coefficient of surface acoustic wave by means of the light diffraction

作　　者：时坚[1] 董军[1] 曾祥梅[1] 苗润才[2] 

机构地区：[1]西安邮电学院电子与信息工程系,西安710121 [2]陕西师范大学物理学与信息技术学院,西安710062

出　　处：《光学技术》2009年第3期377-379,383,共4页Optical Technique

基　　金：教育部骨干教师基金资助项目(2000-65);西安邮电学院中青年教师科研基金资助项目(101-0428)

摘　　要：提出了一种可用于几百赫兹低频液体表面声波研究的激光衍射法测量新技术。在实验上采用入射光掠入射到表面波上在远场得到了中间亮,两边暗的高反衬度的衍射条纹,实验中发现对频率为几百赫兹的低频衰减液体表面波,当移动振源改变激光入射点与振源间距离时发现零级条纹消失,这意味着此时的衍射效率接近100%。在理论上给出了衍射光强度与表面波振幅的解析关系,并利用所提出的新技术实现了对几百赫兹液体表面波的衰减系数的实时测量。A practicable method for liquid-surface acoustic-wave at the frequencies of a few hundreds hertz, based on the optical diffraction, is developed. Diffraction pattern which has high contrast can be taken over in the far fields as the light skim through the low frequency wave. The disappearance of the zero-order diffraction fringe, which corresponding to the 100% diffraction efficiency, is observed for using this technique. Moreover, this technique is used to determine the attenuation coefficient of the surface wave at these frequencies in real time.

关 键 词：表面声波 光衍射 衰减系数 

分 类 号：TN247[电子电信—物理电子学]