Advances in Postprocessing Technology for Laser Ultrasound Detection Signals: A Review

In the field of modern nondestructive testing (NDT), laser ultrasonic detection (LUD) technology has become a remarkable novel technology with its advantages of high-cost performance, noncontact detection, high accuracy, environmental adaptability, etc. Postprocessing of NDT ultrasonic waves to obtain more intuitive information reflecting the acoustic and mechanical properties of objects has also become an important step in modern quantitative NDT and one of the mainstream development directions. This article takes laser ultrasound detection as the entry point, introduces the typical techniques and principles of three major aspects including signal preprocessing, visualization processing, and intelligent defect reconstruction around the postprocessing of laser ultrasound detection signals after reception, compares and analyzes the results of different imaging algorithms, presents the intelligent processing methods commonly used in the field of ultrasound detection defect reconstruction, and briefly summarizes and outlooks on intelligent ultrasound signal processing technology.