Ion implantation can change the mechanical and electrical properties of a material. It is a mature technology that has found many applications, both in industry and in research. We are investigating a new and innovative application of this technology: fine-tuning the optical figure of thin (< 0.5mm) and lightweight (areal density < 1 kg/m2) x-ray mirrors. When successfully developed, this process would be able to significantly improve the fabrication process and the point-spread-function of future x-ray telescopes. This technique could be used as a step of fabricating x-ray optics for future astronomical missions.