Electronic speckle interferometry with pulsed lasers and practical applications

Electronic Speckle Pattern Interferometry (ESPI) with CW-lasers is well introduced in the industry. Using pulse lasers in combination with ESPI techniques expands the technical applications. The combination of double pulse lasers (or multiple pulse lasers) with the ESPI-technique is considered as essential for the industrial application. It expands the application of ESPI systems to the investigation of transient events and the vibration analysis of components under free boundary conditions. However, due to the limited resolution of the CCD-cameras the interferograms show lower signal-to-noise ratio which requests special treatment of the images and new evaluation algorithms, in particular for 3-dimensional analysis. First practical applications have already been carried out in the automotive industry.