Klokov A Yu, Frolov N Yu, Sharkov A I, Chentsov S I, Khmelnitsky R A, Dravin V A
P.N. Lebedev Physical Institute of the RAS, Leninsky Prospekt 53, Moscow 119991, Russia.
Photoacoustics. 2023 Jul 7;32:100528. doi: 10.1016/j.pacs.2023.100528. eCollection 2023 Aug.
Acoustic properties of buried graphitized layers in diamond formed by ion implantation followed by annealing were studied using the picosecond ultrasonic technique with spatial resolution. Two methods of elastic pulse generation were used: heating an aluminum film deposited on a diamond sample by femtosecond laser pulses and direct illumination of the graphitized layers by these pulses. We applied a multilayered model of the acousto-optical response to fit experimental results and estimate the distribution of the acoustical parameters (wave resistance, viscoelastic damping, and longitudinal sound speed) of the structures under study in depth. It was found that unique sets of spectral lines are present in the Fourier spectra of measured responses in regions with different internal structures. Mapping of the Fourier spectra made it possible to visualize regions with different internal structures. The combined use of depth profiling and mapping can serve as a tool for hypersound tomography.
利用具有空间分辨率的皮秒超声技术研究了通过离子注入后退火在金刚石中形成的埋藏石墨化层的声学特性。使用了两种产生弹性脉冲的方法：用飞秒激光脉冲加热沉积在金刚石样品上的铝膜以及用这些脉冲直接照射石墨化层。我们应用了声光响应的多层模型来拟合实验结果，并估计所研究结构在深度上的声学参数（波阻、粘弹性阻尼和纵向声速）分布。发现在具有不同内部结构的区域中，测量响应的傅里叶光谱中存在独特的谱线集。傅里叶光谱的映射使得可视化具有不同内部结构的区域成为可能。深度剖析和映射的结合使用可作为一种用于超声层析成像的工具。
