Laser ultrasound has the characteristics of numerical accuracy and deeper detection depth in residual stress detection. In addition, due to the advantages of non-contact, non-destructive, broadband, and high precision of laser ultrasound, it is easy to apply in harsh environments such as high temperature and high pressure, and can achieve rapid and real-time detection. It has a wide range of application scenarios in the field of non-destructive evaluation and testing.

Laser ultrasound has the following advantages:

1. Non contact, no need for coupling agent, no need to immerse the test sample in coupling liquid for testing, avoiding the possibility of damage to the test sample by the coupling liquid and eliminating the subsequent process of removing the coupling liquid. It is a more suitable testing method for full inspection.

2. It can stimulate very broadband ultrasound signals, increasing the possibility of high-precision imaging of internal defects.

3. Due to the use of laser beams for both excitation and detection, it is possible to reduce the spot size to the micrometer level through optical path focusing technology, thereby improving the spatial resolution of imaging.