Three-dimensional microoptical components embedded in Foturan glass by a femtosecond laser

Three-dimensional (3D) microoptical components are embedded in a photosensitive glass Foturan by a femtosecond (fs) laser. This process includes mainly three steps: (1) direct writing of latent images in the sample by the tightly focused fs laser beam; (2) baking of the sample in a programmable furnace for the formation of modified regions; and (3) etching of the sample in a 10% diluted solution of hydrofluoric acid for the selective removal of the modified regions. After this process, hollow internal structures are formed, which act as a mirror and a beam splitter. Furthermore, we find that postannealing smoothes the surfaces of the fabricated hollow structures, resulting in the great improvement of the optical properties. We examine the optical properties of the structured components using a He-Ne laser beam, and measure the optical losses at 1.55μm wavelength.