Hong Yi, Sharples Stephen D, Clark Matthew, Somekh Michael G
School of Electrical and Electronic Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
Ultrasonics. 2004 Apr;42(1-9):515-8. doi: 10.1016/j.ultras.2004.01.046.
A method has been developed to measure the phase velocity of laser generated and detected surface acoustic waves. An optical grating produced by an electronically addressable spatial light modulator (SLM) was imaged onto the sample surface to generate surface acoustic waves whose frequency and wavefront was controlled by the SLM. When the grating period matched the surface acoustic wavelength, the surface wave was strongly excited, thus the wavelength and, thereby the phase velocity was determined. We present results with this method that allows the phase velocity and the angular dispersion of the generalized surface wave as well as the pseudo-surface wave on the (100) nickel to be measured. Measurements on (111) silicon single crystals are also presented. The measurement precision is approximately 0.2%. Methods to further improve the measurement precision are also discussed.
已开发出一种测量激光产生并检测的表面声波相速度的方法。由电子寻址空间光调制器（SLM）产生的光栅成像到样品表面，以产生表面声波，其频率和波前由SLM控制。当光栅周期与表面声波波长匹配时，表面波被强烈激发，从而确定波长，进而确定相速度。我们展示了用这种方法得到的结果，该方法可以测量（100）镍上广义表面波以及伪表面波的相速度和角色散。还给出了对（111）硅单晶的测量结果。测量精度约为0.2%。还讨论了进一步提高测量精度的方法。
