Ion implanted Bragg endash Fresnel lens

We have investigated the feasibility of widening the bandpath of the Bragg endash Fresnel optical element through the use of ion implantation. The focusing properties of Bragg endash Fresnel lenses (BFLs) were studied as a function of the implantation dose and energy. An enhancement of the focus intensity of up to 15% was found, which is less than expected. Due to the complicated scattering of the low energy ions inside the micrometer- and submicrometer-sized crystal features that make up the BFL relief, the implantation technology destroys the peripheral zones of the BFL more than it increases the intensity in the focus. Nevertheless we believe that high energy implantation can be successfully used to modify the BFL reflectivity, especially in the case of nearly backscattering reflection. copyright 1996 American Institute of Physics