飞秒激光超声时域分析用于无损检测研究

为了进一步探究飞秒激光诱导超声波在无损检测领域中的应用,本文提出了一种基于飞秒激光的超声时域分析方法,实现了对物质的无损检测。该方法首先将飞秒激光聚焦到被测物体表面激发出超声脉冲,然后通过采集超声脉冲的时域信号来对被测物体的内部结构进行可视化无损检测。为了验证方法的有效性,我们进行了以下两个实验:首先,我们对水泥样品进行了扫描并分析得到了其中的孔洞的位置;此外,我们还对未知内部结构的金属镜筒进行了扫描,检测出了其中透镜组的位置。理论分析和实验结果均证明了实验方法的有效性,与传统的超声无损检测技术相比,基于飞秒激光的超声时域分析方法能够简单快速地实现无损检测,具有良好的应用前景。

Ultrasonic time-domain analysis based on femtosecond laser for non-destructive testing

In order to further explore the application of femtosecond laser-induced ultrasound in the field of nondestructive testing,a femtosecond laser ultrasonic time-domain analysis method is proposed to realize non-destructive testing of the measured object in a fast and simple way.There are only two steps in this method.Firstly,the femtosecond laser is focused on the surface of the measured object and the ultra-short ultrasonic pulses are generated.Then the internal structure of the measured object can be detected visually by analyzing the ultrasonic time-domain signals collected by the transducer.In order to verify the effectiveness of this method,we performed two experiments.In the first experiment,a cement sample was scanned and we succeeded to detect the position of the holes in it.And in the second experiment,a metal lens tube of unknown internal structure was scanned and we realized the detection of the position of lens group in it.The theoretical analysis and experimental results both showed that the ultrasonic time-domain analysis method is effective.Compared with the traditional ultrasonic nondestructive testing technology,ultrasonic time domain analysis method based on femtosecond laser can realize high-precision nondestructive testing simply and quickly,which has an important application potentiality.