Method and apparatus for forming periodic structures

摘要

A method and apparatus for directly forming periodic structures on a substrate (111) by laser irradiation comprises directing a linearly polarized laser beam (114) onto a first location of the substrate (111); irradiating the substrate (111) for a sustained duration using the linearly polarized laser beam (114) for melting the substrate (111) at the first location to induce a surface wave thereon; the melted substrate having a plurality of ridges (301a,302a,303a) corresponding to the wavelengths of the surface wave. The linearly polarized laser beam scans the substrate along a first path to propagate the surface wave on the substrate; and thereafter, substrate is cooled down following scanning of the linearly polarized laser for solidifying the plurality of ridges to form a first group of periodic structure on the substrate. Periodic structures formed according to the Invention may be optical gratings such as diffraction or reflective gratings.