Fabrication Of Zirconium Dioxide Diffraction Gratings

Design, analysis and fabrication of Diffraction optical devices are the research frontier of micro-optics and integrated optics nowadays due to their wide applications in modern communication, space technology, microstoning, information processing and biomedicine, and so on. The emphasis of this dissertation is to exploit a novel photosensitive material, and fabricate high performance submicrometer diffraction gratings and arrays combined with laser interference technology. Subsequently, their optical properties are analysed. These studys are of importance to fabricate novel micro-optic devices with the photon as carrier.UV photosensitive Zr-contained sol is synthesized, and photosensitive ZrO₂/BzAc gel films both on silicon and quartz substrates are further prepared using the sol-gel method. The UV and IR spectra indicate that the gel films show the excellent UV photosensitivity. The X-ray diffraction （XRD） result shows that after being heat-treated at 600℃ for 20 min, the inorganic films mainly consist of polycrystalline tetragonal ZrO₂.Homogeneous high density grating can be fabricated by laser interference in ZrO₂/BzAc photosensitive gel films. A two-beam interference system is established and the grating with the minimus pitch of 300 nm is obtained using this system, which also indicates that linear optical revolution of the gel films is less than 150 nm. Furthermore, two-dimensional lattice and dots array are also produced by double exposure.A novel four-beam interference system is proposed, which is used to fabricate two-dimensional Bragg Grating with a pitch of 1000 nm successfully. From the micrographes, it can be seen that the lattices consist of round holes with sharp edge. Compared with the double exposure of two-beam laser, better modulation and precision can be obtained by four-beam laser interference. Diffraction properties and efficiencies of the gratings are measured systematically. The results show that diffraction of the gratings conforms to the Multiple-Slit Interference Effect, and the diffraction efficiency is related to depth-to-width radio of the grating, which can be increased obviously after being gold coated.