Nondestructive testing of aerospace composites with an infrared matrix laser vibrometer

We describe a hybrid system for real-time, full-field vibrometry, incorporating features of high-speed electronic speckle pattern interferometry (ESPI) and laser Doppler vibrometry (LDV). Based on a 2D interferometric sensor array, comprising 16 × 16 parallel illumination and detection channels, the matrix laser vibrometer (MLV), captures full-field data instantaneously, without beam scanning. The instrument design draws on the advantages of scale offered by modern telecommunications fiber optic and digital electronics. The resulting architecture, comprising a compact measurement probe linked by fiber optic umbilical to a remote electronics unit, facilitates practical application of the system in fullfield measurement of transient vibrations and rapid non destructive testing of composite materials.