Nanosized modification of transparent materials using femtosecond laser irradiation

Abstract

We show a novel method of fabricating a periodic nanovoid structure inside commercial borosilicate glass using femtosecond laser irradiation. The aligned voids are formed spontaneously with a period of micrometer length along the propagation direction of the fs laser beam. In addition, structure parameters of the void array, i.e., the period between voids, the number of voids, and the entire length of the aligned structure, can be controlled by adjusting the laser irradiation conditions. In addition, cross-shaped pattern due to local dislocations can be formed spontaneously inside MgO single crystal using fs laser irradiation. The ability to easily fabricate such controllable periodic void or crossshaped pattern guarantees applicability in optoelectronics areas, such as 3D photonic crystals and polarizer.