Enhanced Laser-Based Magneto-Optic Imaging System for Nondestructive Evaluation Applications

An enhanced and innovative laser-based magneto-optic (MO) imaging (LMOI) system is presented in this paper to detect buried subsurface flaws in metallic structures for structural nondestructive evaluation. Several key improvements for the new imaging device have been discussed, including the following: the optimization of the MO sensor, the design of the magnetic excitation device, and the development of the image processing approaches, which result in the enhanced MO image quality comparing to the first generation of LMOI. Experimental data have also been obtained that clearly demonstrated the improvement in imaging results.