Study of compositional changes of (Ag-)Sb-S thin films after Ar+ ion laser irradiation by means of micro X-ray fluorescence

Thin amorphous films from (Ag-)Sb-S system were prepared as potential candidates for new phase-change memory films. Amorphous (Ag-)Sb-S thin films were deposited by thermal evaporation (TE) of Sb33S67 bulk sample followed by optically induced diffusion and dissolution (OIDD) of thermally evaporated Ag thin films. The phase-change recording process was realized via photocrystallization experiments done by Ar+ ion dot laser exposures of prepared films. Morphology of the laser exposed dots was observed by transmission optical microscopy while micro X-ray diffraction (:-XRD) was utilized for determination of crystallinity of the exposed dots. Laser induced changes were quantified by local measurement of optical transmission in dependence on laser exposure time. Compositional changes are determined via micro-X-Ray Fluorescence (:-XRF). The results prove crystallization of laser exposed thin film. Kinetic of this process is described in terms of transmittance change, evolution of X-Ray diffractograms and changes observable by optical microscopy. Moreover, the results do not indicate any significant chemical change in the case of stoichiometric Sb2S3 after laser irradiation while certain migration of silver takes place in sulfur rich Sb-S films doped by Ag

Ge-Sb-Te thin films deposited by pulsed laser: An ellipsometry and Raman scattering spectroscopy study

International audiencePulsed laser (532 nm) deposited Ge2Sb2Te5 thin films were investigated by means of spectroscopic ellipsometry and Raman scattering spectroscopy. Tauc-Lorentz and Cody-Lorentz models were employed for the evaluation of optical functions of thin films in as-deposited (amorphous) and crystalline (cubic) phases. The models' parameters (Lorentz oscillator amplitude, resonance energy, oscillator width, optical band gap, and Urbach energy) calculated for amorphous and crystalline states are discussed. The vibrational modes observed in Raman spectra of amorphous layers are attributed to GeTe4-nGen (n=1, 2, eventually 0) tetrahedra connected by corners (partly by edges) and SbTe3 units. The Raman spectra of crystalline thin films suggest that the local bonding arrangement around Ge atoms changes; GeTe component is thus mainly responsible for the phase transition in Ge2Sb2Te5 alloys

Erbium doped germanium based sulphide optical waveguide amplifi er for near- and mid-IR

conference 7366 " Photonic Materials, Devices, and Applications ", Session " Posters-Tuesday " [7366-65], http://spie.org/microtechnologies-new-millennium.xmlInternational audienceDue to remarkable properties of the chalcogenide glasses (Chgs), especially sulphide glasses, amorphous chalcogenide films should play a motivating role in the development of integrated planar optical circuits and their components. This paper describes the fabrication and properties of optical waveguides of undoped and erbium doped sulphide films obtained by RF magnetron sputtering and laser ablation (PLD). The deposition parameters were adjusted to obtain, from sulphide glass targets with a careful control of their purity, layers with appropriate compositional, morphological, structural characteristics and optical properties. A transmission loss of 0.8 dB/cm can be obtained for rib waveguides produced by dry etching under CF4 plasma (4-300 μm wide, 5.5 μm film thickness, 1.5 μm etched thickness). The photo-luminescence of erbium doped Ge20Ga5Sb10S65 films were clearly observed in the n-IR and mid-IR spectral domain. The study of their decay lifetime with a well adapted annealing treatment controlling the roughness variation reached value of the bulk counterpart. Amplification tests were carried out leading to a complete characterisation of the Erbium doped waveguide. Gain on/off of 4.4 dB (3.4 dB/cm) were achieved for a signal at 1.54 μm in multiple modes sulphide:Er waveguides. The first demonstration of photoluminescence in mid-IR in an Er3+- doped Chg waveguide could potentially be employed to produce sources or amplifiers operating in the mid-IR

Guide d'onde de sulfures à base de germanium dopé Er3+ pour amplification dans le proche et moyen-IR

session affiches 9 "Optique intégrée et propagation guidée " [A9.4]National audienc

Chalcogenide films for photosensitive band-pass filters and opto-chemical sensors application

Topic: Optoelectronic Materials and Devices, conference 6890 " Optical Components and Materials V ", session 2 " Glass Photonic Devices " [6890-11], http://spie.org//x19316.xmlInternational audienc