Embossing technique for fabricating integrated optical components in hard inorganic waveguiding materials

We describe a novel embossing technique for fabricating integrated optical components in hard and resistant inorganic waveguiding materials of good optical quality. The desired structure is embossed into a dip-coated deformable gel film prepared from organometallic solutions. Subsequent heat treatment transforms it into inorganic hard oxide material. We have successfully fabricated surface-relief gratings with 1200 lines/mm on SiO(2)-TiO(2) waveguides (with refractive index n(F) approximately 1.8, thickness d(F) approximately 120 nm, and loss <1 dB/cm). The embossed gratings served as input and output grating couplers and as Bragg reflectors. We propose to fabricate other integrated optical components, for example, channel waveguides, with this method.