Surface-Displacement Imaging Using Optical Beam Deflection

Important information on subsurface material parameters and structure is contained in the dynamics of surface motion. One of the most important techniques in quantitative nondestructive evaluation is optical sensing of surface displacement; it is noncontact, sensitive, fast, and capable of high spatial resolution. Laser interferometers in various configurations provide the ultimate in sensitivity [1]; however, due to their complexity and lack of flexibility, they may not be the first choice in applications where ultimate sensitivity is not required