Detection of fatigue damage in steel using laser speckle

A techniciuc for all-optical laser cleaning and surface quality monitoring of concave metal surfaces is suggested. Contaminated pharmaceutical punches from a tablet compression machine were cleaned using high-energy laser pulses. Image information obtained from a diffractive-optical-element-based sensor was used in inspection of the surface quality change of the concave punches due to laser cleaning. Alternative method for mechanical cleaning of punches is introduced, which is based on simultaneous laser cleaning and surface quality inspection of the punches.