Fabrication And Luminescent Properties Of Rare-earth Doped Chalcogenide Films

Chalcogenide glass is considered to have broad application prospects in the infrared transmission material and host material of infrared laser, with many unique optical properties, such as lower phonon energy, excellent infrared transpraceny, good chemical durability and thermal stability. With the development of modern science and technology, need for integrated optical devices become higher and higher, then the preparation of glassy film is required. Theoretically, the film appears obvious changes in microstructure and macroscopic properties compared with glass materials.Some chalcogenide glasses and chalcogenide semiconducting films stand out excellent hosts for multiple rare earth (RE) dopants due to their low phonon energy, large refractive index, excellent transparency in the infrared (IR) region, and high RE solubility.This opens a way to highly integrated planar waveguide devices for optic amplification, sensing, and lasing with a view to miniaturizing the device size on a single chip.In this thesis, high-quality uniform Ge-Ga-based amorphous chalcogenide films co-doped with Tm3+-Dy3+were fabricated by pulsed laser deposition and characterized with XRD(X-Ray diffraction), SEM(Scanning electronic microscope), AFM(Atomic force microscope), XPS(X-ray photoelectron spectroscopy analysis), Raman Spectra. Characterization results indicated that the as-prepared film was amorphous, homogeneous and packed texture, its thickness reached to700nm with a short-cut wavelength placed at about500nm while its average transmittance was higher than75%; Compared with the glass target, the structures of the film differed little, but not so obvious. The film shows the remarkable superbroadband (from1050 to1570nm) NIR emission and the intense broadband NIR emission centered at～1800nm, covering the whole low-loss wavelengh region of silica optical fibers. This is contributed by the Tm3+sensitization and the efficient energy-transfer process from Tm3+to Dy3+, which is verified by the broad-range excitation near Ulbach optical-absorption edge. In addition, when the films were covered by Ag films, the RE3+luminescence changed thanks to the effect of the surface plasmon polarization of Ag nano-islands. These results make the codoped chalcogenide films as promising candidates for developing highly integrated planar optical devices, such as broadband planar amplifiers and tunable IR lasers.