A method of formation of nanowires at a surface of a substrate attached to a solid immersion lens. The method includes formation of a catalyst element at the surface of the substrate and growth of nanowires from the catalyst element formed at the surface of the substrate. The catalyst element is a metal nanoparticle and the formation of the catalyst element at the surface of the substrate deposits the metal nanoparticle using a light beam focused by the solid immersion lens at the surface of the substrate.