PbTe films have been deposited on glass substrates by laser ablation from PbTe pellets pressed from high purity Pb and Te powder. X-ray diffraction experiments and optical characterization of the films have been performed as a function of evaporation conditions (pellet composition and substrate temperature). From transmittance and reflectance measurements the values of the absorption coefficient $\alpha $, of the refractive index n, and of the extinction coefficient k have been calculated.

Thin films of Zn$_{1-x}$ CdxO with x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5 at.% were deposited by electron-beam evaporation technique. It has been found that, for as-deposited films, both the transmittance and electrical resistivity decreased with increasing the Cd content. To improve the optical and electrical properties of these films, the effect of annealing temperature and time were taken into consideration for Zn$_{1-x}$ CdxO film with x = 0.2. It was found that, the optical transmittance and the electrical conductivity were improved significantly with increasing the time of annealing. At fixed temperature of 300 °C, the transmittance increased with increasing the time of annealing and reached its maximum values of 81% in the visible region and 94% in the NIR region at annealing time of 120 min. The low electrical resistivity of 3.6 × 10−3 Ω cm was achieved at the same conditions. Other parameters named free carrier concentrations, refractive index, extinction coefficient, plasma frequency, and relaxation time were studied as a function of annealing temperature and time for 20% Cd content.

The effect of thermal annealing on the structural properties of electron beam evaporated polycrystalline Si/Ge multilayer structures has been studied using Grazing incidence X-ray diffraction (GIXRD), reflectivity (GIXRR) and Raman spectroscopy techniques. The chemical nature of layers at surface and interfaces has been obtained from X-ray photoelectron spectroscopy (XPS) technique, which revealed the presence of impurities only at the top surface in the form of carbides and oxides in the Si layer and in elemental form in the Ge layer. Reflectivity measurements show that the Si/Ge MLS is stable upto 200 °C and roughness of Si on Ge interface is higher as compared to that of Ge on Si interface. Similarly, GIXRD results show that upto 200 °C, MLS is of microcrystalline nature and further annealing at 300 °C and 400 °C, well-defined crystalline peaks of pure Si and Ge are observed, which is in contrast to earlier reported experimental findings. Observed results are interpreted in terms of diffusion induced crystallization and corresponding increase in grain size.

We describe the design and performance of a slow atom source based on a 2D magneto-optical trap (MOT) that uses an innovative simple optical configuration. Metal-coated retro-reflecting prisms replace mirrors and quarter-wave plates so the optical power of the cooling laser beam is recycled. This source has been characterised for three different configurations: with and without transverse magnetic field gradient, and with a pusher beam to obtain a 2D+-MOT. The longitudinal velocity is of the order of 25 m·s−1, with a transverse velocity spread ≤1 m·s−1, while the typical atomic flux density obtained is up to 1.3×1014 at ·s−1·m−2 for a cesium vapour pressure of ~4×10−8 mbar in the source. We use this slow atom beam, instead of cesium vapour, to load a 3D moving optical molasses that feeds a continuous cold atom fountain. We obtain a gain of a factor ~20 in the atomic flux launched by the fountain.

Thin films of thulium and samarium doped AlN are deposited on silicon (111) substrates at 77 K by rf magnetron sputtering method. 200–400 nm thick films are grown at 100–200 watts RF power and 5–8 mtorr nitrogen, using a metal target of Al with Tm and Sm separately. X-rays diffraction results show that films are amorphous. Cathodoluminescence studies are performed at room temperature and two dominant peaks are observed in Tm at 467 nm from $^{1}{\rm D}_{2}$$\to$$^{3}{\rm F}_{4}$ transition and 480 nm from 1G4 to the ground state 3H6 transition. Other peaks in the visible region are obtained at 650 nm and 685 nm due to $^{1}{\rm G}_{4}$$\to$$^{3}{\rm F}_{4}$ and $^{1}{\rm D}_{2}$$\to$$^{3}{\rm H}_{4}$ transitions. Peaks in the ultraviolet and infrared region are also obtained at 371 nm, and 802 nm as a result from $^{1}{\rm D}_{2}$$\to$$^{3}{\rm H}_{6}$ and $^{3}{\rm H}_{4}$$\to$$^{3}{\rm H}_{6}$ transition respectively. Sm gives four peaks at 564 nm, 600 nm, 648 nm and 707 nm as a result of $^{4}{\rm G}_{5/2}$$\to$$^{6}{\rm H}_{5/2}$, $^{4}{\rm G}_{5/2}$$\to$$^{6}{\rm H}_{7/2}$, $^{4}{\rm G}_{5/2}$$\to$$^{6}{\rm H}_{9/2}$ and $^{4}{\rm G}_{5/2}$$\to$$^{6}{\rm H}_{11/2}$ transitions. Films are thermally activated at 1200 K for half an hour in a nitrogen atmosphere. Thermal activation enhances the intensity of luminescence.

An electron diode having a ferroelectric plasma cathode (FPS) controlled by optic fibers was operated at a repetition rate of 0.5 Hz during 1 hour, when an accelerating pulse of ~250 kV in amplitude and ~250 ns in duration is applied. The application of the fiber optic decoupling allows easy control and synchronization of the FPS operation with the firing of the HV generator. It was shown that the use of the FPS with fast fall time of the driving pulse allows reproducible generation of an electron beam having a current amplitude of ~1 kA and uniform cross-sectional current density distribution. It was shown also that in the case of the driving pulse ringing, the application of the accelerating pulse during the fall in the negative ringing leads to a plasma pre-filled mode of diode operation due to intense ion emission from the FPS. When the accelerating pulse is applied during the rise in the positive driving pulse ringing, one obtains diode operation with limited plasma emission ability. Only when the accelerating pulse is applied during the fall in the positive ringing of the driving pulse does one obtain diode operation in space-charge limited mode. This dependence of the diode operation on the timing of the accelerating pulse application with respect to the driving pulse is explained by processes related to the screening of ferroelectric bounded surface charges by the plasma charged particles.

A kinetic model and the associated PIC-MCC numerical technique have been used to simulate the plasma generated by a vacuum arc cathode spot fragment and calculate the current densities and net energy fluxes at the cathode surface. The model is based on a comprehensive description of the plasma generation processes, including a detailed representation of metal vapor particle ionization and plasma-cathode interaction. An important feature of this model is its ability to provide details of the spatial variations of plasma parameters within the near cathode region. Calculations are carried out for nickel, titanium and zirconium cathodes as a function of the surface temperature. It is found that below a threshold surface temperature the energy input to the cathode is negative and the spot fragment can not operate in a self-sustained way. The relative importance of the different mechanisms controlling current and energy transfers at the cathode surface are analyzed in detail.

The aim of this paper is to define a linear model of a planar standing wave ultrasonic motor (SWUM). First, the analytical approach using the variational formulation is presented. An identification method is deduced to find the parameters of a vibrating rectangular plate. Non-linearities are also emphasized and verified by the experimental measurements. Secondly, the mechanical energy conversion of the actuator is identified, using an average behavior modelling and a linear approach for the contact interaction. Finally, a complete modelling of the actuator is presented, using the Causal Ordering Graph formalism.

In order to meet absolute metrology of displacement in several axes simultaneously; the induced errors due to the fluctuation of atmospheric parameters and Doppler effect should be investigated. Measurements of phase dispersion and Doppler frequency shift over two different axes using dual-wavelength laser heterodyne interferometer (ZMI-1000A) are reported. The principle of this work is to study the induced parameters influences of an absolute measurement of a displacement over two different axes in a free atmosphere using laser heterodyne interferometer.