New approaches to defect characterisation with high resolution non-contacting laser ultrasound

This paper discusses how laser ultrasonic imaging technology may be used for defect detection. The poor single to noise ratio and the consequent potential for damage to the sample have hindered the widespread application of laser ultrasound. We discuss how our approach overcomes many of these problems. Moreover, we discuss the specific and potentially important advantages that arise from the frequency flexibility, absence of couplant and the ability to control the generated wavefront.