Multi-detector receiver for laser ultrasonic measurement on the run

Laser-based ultrasonic (LBU) is now becoming a more mature technology, making the transition from research laboratory equipment to an industrial on-line measurement system. The non-contact and remote capability of LBU is an undeniable advantage for high-speed inspection. As LBU competes with other inspection technologies for on-line integration, LBU must retain its performance advantages despite operating in a far from ideal environment. In this paper, we review recent developments in a receiver based on multi-detector elements, which was specifically developed to meet the demanding needs of industrial inspections. We show that by integrating detector arrays into a classic interferometer design, we can transform a high sensitivity but delicate laboratory interferometer into a rugged system capable of enduring tough industrial environment.