Electronic holography and shearography NDE for inspection of modern materials and structures

Coherent optical techniques such as holography, shearography, and ESPI have been available for inspection applications for years. However, they are still not well known or widely used. In fact, they have sometimes been described as “a solution looking for a problem” and like so many new technologies, they may have been somewhat oversold. These optical NDE methods do, however, offer some impressive advantages over more conventional inspection techniques for the right applications. It is the intent of this paper to provide some basic information on how two of these optical methods, holography and shearography, work discuss capabilities and limitations of both, present the electronic holography and shearography inspection system developed by UTRC/Pratt & Whitney, and provide some examples of successful applications of both