The detection of crack on materials is an important issue in industry. On the contrary to conventional methods, such as manual inspection, sensor detection, and image processing techniques, a new simple method to detect the crack is proposed with optical voice recorder based on digital holography in this paper. Holograms obtained with sound waves passing through the materials are recorded by using the digital holography technique. Temporal behavior of the sound wave passing through the material, which is obtained from these holograms, gives image of crack. In this article, cracks in various materials are determined by the proposed new method, and crack images obtained with this new system are presented.

高速变焦液体透镜在快速移动物体的目标捕捉方面具有重要的应用。高频声波激励方法在理论上能够实现毛细腔边沿(靠表面张力)约束液滴的高速往复运动, 但是相关工艺试验研究是目前该技术成熟应用的关键。文章在对毛细腔贯通液滴共振理论分析的基础上, 基于3D打印技术开发了一种采用双源声波激励毛细腔贯通液滴进行振动的实验装置。在分析能量损失的基础上, 采用激光多普勒测振仪分析了相关工艺参数对毛细腔贯通液滴振动频率和振幅的影响, 总结了相关规律, 为实现高速变焦液体透镜技术的应用奠定了基础。

基于光电接收目标的漫反射光原理,采用红外激光探测室内声波,在对目标特性研究和漫反射回波信号光功率估算的基础上,设计和研制了实验系统。用红外激光探测从玻璃目标返回带有受声波调制的激光漫反射回波信号,在6～63 m距离及直接反射光线与探测器光轴之间的夹角β≤±4°时,可以听见所探测到回波信号中的声音；当β=4°～15°时,可以探测到激光漫反射回波信号,但听不到声音。实验证明,利用漫反射激光探测室内声音的方法是可行的。

介绍了激光窃听的基本原理,归纳了该技术的特点,并提出了激光窃听的实现方案.

应用脉冲载波电子散斑干涉(pulsedcarried-ESPI)与计算机层析技术(CT),实现了由高压电极放电激励所产生的瞬态传输声场在经过不同孔径模板衍射后波前与压力场的三维重建,给出了数值结果,并对噪声条件下的计算机层析重建进行了讨论。