ION-IMPLANTED BRAGG-FRESNEL LENS

We have investigated the feasibility of widening the bandpath of the B ragg-Fresnel optical element through the use of ion implantation. The focusing properties of Bragg-Fresnel lenses (BFLs) were studied as a f unction of the implantation dose and energy. An enhancement of the foc us intensity of up to 15% was found, which is less than expected. Due to the complicated scattering of the low energy ions inside the microm eter- and submicrometer-sized crystal features that make up the BFL re lief, the implantation technology destroys the peripheral zones of the BFL more than it increases the intensity in the focus. Nevertheless w e believe that high energy implantation can be successfully used to mo dify the BFL reflectivity, especially in the case of nearly backscatte ring reflection. (C) 1996 American Institute of Physics.