Micro-displacement measurement by means of moir� patterns, using two Fresnel zone plates

An optic system is developed and it measure the micro-displacement in a body under stress, with the use of moir� interference. We designed a Fresnel zonal plate to form interference patterns by means of the overlapping of a couple films. After plates designed, some of them is fixed and the other one is subject to a body willing to being compressed. The compression of the body will make the necessary movement to appreciate the phenomenon of moir� interference, ie, with the displacement in one of the zonal plate, we will obtain the moir� interferometric patron. � 2008 Society for Experimental Mechanics Inc