Study of Crack Growth of Transparent Materials Subjected to Laser Irradiation by Digital Holography

Abstract

The crack growth of transparent materials after laser wavelength irradiation was studied. It is known that laser irradiation is used in many applications for the ablation of undesired material and/or coatings. The impact of laser irradiation on cracks was studied using the digital holography (DH) technique. Transparent samples were irradiated using near-ultraviolet, visible, near-infrared, and infrared light. The DH system is able to detect cracks and crack growth of the transparent samples irradiated by a range of laser wavelengths. Results also show that light with infrared to near-infrared wavelengths has a great effect on crack growth. High-resolution photomechanical effects of laser irradiation on material expansion or/and generation of defects due to specific wavelengths are also illustrated. The DH system with a multispectral laser has practical applications for laser cleaning of painted artworks.

Speckle pattern interferometry excited by pulsed laser for crack size detection

“…And different defect types are characterized by variability of influence to integrity of precious object. Crack is a common studied type in defect inspection and its weaken effect to material structure has been studied before 1,2 . For avoiding and reducing damage caused by cracks, researches on efficient methods to locate defects position and measure defects size quantitively have significant values.…”