ĂŽČ›i doreČ™ti o piele netedÄ, catifelatÄ, fÄrÄ celulitÄ? Ai Ă®ncercat Lirene?
Author s : Serban Georgescu; Voicu Lupei ; Claudiu Hapenciuc Show Abstract A mathematical model, based exclusively on spectroscopic data concerning radiative, non-radiative, and energy transfer processes, is proposed and used to simulate the Q-switch regime of three-micron Er:YAG laser.
The radiative as well as non- radiative losses during optical pumping and giant pulse generation are defined and evaluated. The reasons responsible for experimental performances of Q-switched Er:YAG lasers inferior to those predicted by the mathematical modeling ratu slimming jelly instagram analyzed. Author s : Valerica Ninulescu; Paul E.
Sterian; Mihaela A. Ghelmez ; Mihai C. Piscureanu Show Abstract The work addresses the problem of a CO2 laser dynamics control in the presence of Gaussian white noise in the cavity losses. We improve the delayed continuous feedback method by introducing memory of the previous states. The method proves a powerful one that works for otherwise chaotic dynamics and regular dynamics equally well and it is robust with respect to noise.
Sporea ; Clementina A. Timus Show Abstract The paper describes the methods used to adapt an industrial TEA- CO2 laser to the requirements of the ISO standard 11 for a laser induced damage threshold experimental facility.
The goals were to improve the pulse energy stability and the laser beam spatial profile and the methods were: 1 finding the best discharge voltage; 2 adapting the laser cavity, 3 using suitable apertures.
There is also presented the experimental set- up for beam characterization, which included a laser beam profiler a line of 60 pyroelectric detectorsan energy-meter to monitor the pulse energies and KCl optical components for beam splitting and beam guiding. Every beam distribution was regarded as a linear combination of normalized Gauss-Hermite functions and the fitting algorithm allows the calculation of the coefficients of this combination.
Author s : Niculae N. Puscas ; R. The simulations show the evolution of the above mentioned parameters under various pumping regimes. In the present work we demonstrated that high gains and low noise figures are achievable in high pump regimes and double pass configuration.
Author s : Nicolaie A. Pavel; Takunori Taira ; M. Using M2 factor to describe the multimode pump beam's propagation from the broad-emission-area diode-laser the coupling optics was designed to obtain a high value for the mode-matching pierderea în greutate ajutor apps. A maximum slope efficiency of eta s equals Author s : V.
Stancalie; Alain Sureau; V. Burke Show Abstract Within the framework of x-ray laser research using the recombination of heliumlike ions with free electrons to produce lithiumlike ions in expanding and cooling hot plasmas, we present a set of ratu slimming jelly instagram data required to improve the gain modeling.
We estimate the cross section and rate for ion-impact excitation in aluminum Ratu slimming jelly instagram lasing medium using the two-state approximation for transitions caused by a multipole interaction.
The approximation used for atomic data calculation is presented.
Carti Editura: Ig Publishing, Availability: In stoc
Author s : Anca Mocofanescu ; Vasile D. Q-switching is provided by a nonlinear LiF:F2- crystal before the stimulated Brillouin scattering takes place. Employing proper mode selectors pulses with 6 mJ minimum energy and duration of 20 ns were generated, the beam divergence being 1.
A new theoretical model of the Q-switching regime has been proposed and good agreement between experimental and theoretical data has been obtained. Sandrock; Ernst Heumann; Guenter Huber Show Abstract The features of a new upconversion mechanism of excitation, the sensitized photon avalanche, are discussed on the basis of a ratu slimming jelly instagram equation modeling.
In this process the excited state absorption ESA from a metastable level reservoir of the active ion is enhanced by a cross-relaxation between the emitting level ratu slimming jelly instagram this ion and the sensitizer ion which is able to transfer subsequently the accepted excitation back into the reservoir level of the activator; the donor act of the cross-relaxation ends on this reservoir level too.
When the efficiencies of these two energy transfer processes are larger than specific threshold values related to the intrinsic de-excitation rates of the emitting level of activator and of the excited level of sensitizer, a process of population of the reservoir level with a quantum efficiency larger than the unit for each act of de-excitation of the emitting level takes place.
Further on, if the ESA rate exceeds a threshold value determined by the intrinsic de- excitation of the reservoir and by the efficiencies of the energy transfers an avalanche population of these levels could take place. This process could be used for infrared pumping of visible solid state lasers.
Referințe bibliografice pe an
Author s : Emil Smeu ; Niculae N. Puscas ; Ion M. Popescu; Grigore I. Suruceanu ; Radu G. Ispasoiu Show Abstract Power stabilized DL's represent today convenient sources for radiometric applications, as transfer laboratory standards. Stability measurements were carried out and reported by other authors for different time intervals, but only for low optical power levels max.
For calibrating usual optical radiometers, such low emitted power DL's are useless. Stabilities of the order 1e-4 for short-time intervals tens of seconds and 1e-3 for medium-time intervals 1 hour were found for a non-thermostated structure, having the control photodiode PD in the same enclosure with the DL at the rear of the structure.
The corresponding stabilities for an external control PD resulted of the order 1e-5 for both short and medium time intervals. The schematic of the optical power stabilizer is presented.
Cristescu; Alexandru M. Preda Show Abstract A simple and inexpensive method to perform high resolution spectral studies of the green-yellow pulse shapes of a CuBr laser is presented. The individual The RF spectral analyses of the compound signal the weighted sum of the two pulses, one of them being delayed with respect to the other one reveals that the coherence properties of the spectral components are dependent both on the pulsed mode excitation and the optical modes supported by the optical cavity.
Pavel; Takunori Taira ; Traian Dascalu; Voicu Lupei Show Abstract In order to describe the transversal mode construction in a real laser resonator, a mathematical model was investigated.
The analysis use Kirchhoff-Fresnel diffraction equation and amplification processes in the active medium, that was supposed as sum of thin discs with gain and losses constants on every disc's length.
Influence of additional phenomenon on laser beam characteristics, as phase-shift caused by active medium thermal induced refractive power and curvature of the resonator mirrors were considered. Author s : Rodica V. Baltateanu Show Abstract High power pulsed laser diodes are of interest due to their potential use in medicine and peculiar applications.
The damaged devices were investigated by optical and scanning electron microscopy and there was performed a electron dispersion spectroscopy analysis. These experiments advanced the idea ratu slimming jelly instagram dividing catastrophic degradation in three types, respectively: 1-catastrophic optical mirror damage, 2-catastrophic damage due to major mechanic defects, 3-catastrophic damage due to metal migration e.
There was established an experimental criterion to characterize catastrophic damage. Author s : Aurel Stratan ; Constantin G. Fenic ; Razvan V. Dabu; Nicolae A. Herisanu; C. Luculescu; Dan G. The pump system includes a pair of 1 W diode-arrays mounted in coaxial enclosures, a driver unit and the pump optics. The array wavelength was temperature tuned to achieve the maximum absorption of the pump radiation in the Nd:YAG crystal. The characteristics of the pump system are presented and the pump-beam profile is investigated.
For a He pressure of 20 Torr and a current of mA, the laser power was 28 mW on seven lines in the blue-green region.
By spectroscopic measurements we have determined the influence of metal vapor presence on the intensity of a helium line.
Some modifications of the vapor clouds generated by a magnetic field are reported. Author s : Voicu Lupei ; Eugen Osiac Show Abstract The paper discusses the effect of pump intensity variations caused by absorption in a fiber system with upconversion avalanche fluorescence or laser emission.
The numerical modeling shows ratu slimming jelly instagram in given pump conditions the initial part of the fiber up to a distance zth is pumped above the avalanche threshold while the remaining part lies below it. This induces a strong variation of populations of the excited levels along the fiber.
The characteristics of the avalanche emission are connected to the spectroscopic parameters of the system and to the conditions of pump. The effect of distribution of local pump intensities on laser emission in avalanche-driven upconversion fiber lasers is also discussed.
Simultaneously, both types of the gain and refractive index asymmetries of the active medium parallel and perpendicular on the flow direction are compensated.
A 90 degree s deflection device is the main constructive element this is built by two mirrors at 45 degree s relative angle and offers the pentaprism properties. This deflection device reverses the wavefront in one of the two discharge channel and in addition improved the resonator stability.
The main results are eta m is congruent to 0. The comparison shows good agreement between the simulation results under specific conditions. A special accent is placed ratu slimming jelly instagram the advantages and drawbacks of both methods by taking into account their ratu slimming jelly instagram problems and the computational effort implied by simulations.
Author s : Voicu Lupei ; Serban Georgescu Show Abstract A generalized model of the cw three-micron emission in concentrated Er systems, which takes into account the whole variety of de-excitation processes is presented. The analytical equation for the flux of light enables a direct correlation of the parameters of emission threshold, slope efficiency with the spectroscopic parameters and pump conditions. The effect of excited state absorption is, also, put in evidence.
Author s : Ashock Kumar; H. Chan; Rodica Alexandrescu Show Abstract Carbides and nitrides of metal have a large number of 12 pierdere în greutate nou născut in modern technology owing to their interesting, and in some ways unique, physical and chemical properties.
Thin film coatings of titanium carbide and aluminum nitride were deposited on Si substrates using pulsed laser deposition method. The structural and microstructural properties of these films have been characterized using x-ray diffraction, and Fourier transform infrared spectroscopic techniques. The mechanical properties of the films were evaluated to measure the hardness and modulus values.
It has been shown that the films deposited at higher temperature have the best crystalline quality structure and also have higher hardness values compared to the film deposited at lower temperatures. Author s : Alessio Perrone Show Abstract The effects of laser fluence on the structure and properties of the reactive pulsed laser deposited carbon nitride CNx thin films prepared at different gas pressures of N2 and NH3 were investigated.
The structure, the morphology and the chemical composition of the films were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Rutherford backscattering and Fourier transform infrared. The films were plane, adhesive and relatively hard, with a low droplet density. The nitrogen concentration in the deposited films drops when the substrate temperature is increased, indicating a desorption process of the CN radicals.
Spectroscopic studies of the plasma plume indicates an interesting correlation between the CN band emission intensity and the nitrogen concentration in the samples. Author s : R. Klein-Douwel; J. The method and results of diamond growth are discussed, as well as the 2D-LIF technique. The distributions of atomic hydrogen, CN, and C2 in the flame are presented together with their relations to diamond growth.
Ratu slimming jelly instagram T.