Erzeugung und Nachweis von Ultraschall mit optischen Methoden

An overview is given about laser ultrasonics and its applications. For the effective excitation of ultrasound a proper choice of the pulse laser's wavelength and energy with respect to the application considered is necessary. For industrial applications the Fabry-Pérot interferometer has been shown to be most effective. Ultrasonic displacements in the range of an A can be detected at a receiving bandwidth of 10 MHz. The laser ultrasonic technique is an established nondestructive method for the flaw inspection of curvatured parts of fiber reinforced polymers used for aerospace applications. The wall thickness measurement of hot tubes in the process line is under development. Further applications are found in the field of material characterization especially in the case of high temperatures.