Solid lasers materials

Those rates are inherent to any specific set of levels and determined by the nature of the atomic structure for that species and electron configuration. The natural linewidth can vary anywhere from 10 Hz in the infi ared to 10 Hz in the soft X-ray spectral region, and the actual linewidth can increase to as high as lO -lO Hz or more if col-lisional broadening occurs in high-density liquid or solid laser materials. 

F. Hide, M.A. Dtaz-Gatcia, B.J. Schwarts, M.R. Andersson, P Qibing, A.J. Hecger, Semiconducting polymers a new class of solid-state laser materials. Science 1996, 273, 1833. 

Also, direct determination of additives by means of laser desorption in solid polymeric materials rather than in polymer extracts has been reported [266], Takayama et al. [267] have described the direct detection of additives on the surface of LLDPE/(Chimassorb 944 LD and Irgafos P-EPQ) after matrix (THAP)-coating. As shown in Scheme 7.13, direct inlet mass spectrometry is also applicable to transfer TLC-MS and TLC-MS/MS analyses without the need for prior analysis. For direct sample introduction a small amount of the selected... 

The latest advancement in femtosecond (fs)-based micromachining technology has opened a new window of opportunity for fabrication of microdevices. Direct exposure of most solid materials (including fused silica glass) to high power fs laser pulses may lead to the ablation of a thin layer of materials at the laser focal point13. Due to the multiphoton nature of the laser-material interaction, the ablation process can be conducted on the material surface as well as within its... 

The choice of sensor material determines range, sensitivity, and stability. By considering the latter factors, it is found that inorganic insulating compounds, such as most lamp phosphors and many solid state laser materials, are the most suitable materials for thermometric applications. Indeed, these materials are most commonly used in the existing commercial fluorescence thermometer schemes. 

The yttrium aluminum garnet crystal, Y3 AI5O12, doped withNd + ions, is a well-known solid state laser material (abbreviated to Nd YAG). If the fluorescence lifetime of the main laser emission is 230 /rs and the quantum efficiency of the corresponding emitting level is 0.9, determine (a) the radiative lifetime and... 

Powell, R. C., Physics of Solid-State Laser Materials, AIP Press/Springer, New York (1997). Riseberg, L. A., and Weber, M. J., in Progress in Optics 14, ed. E. Wolf, North-Holland, Amsterdam (1975). 

Most of the solid-state lasers employ as active material crystals or glasses doped with rare-earth or actinide ions, because these ions exhibit a large number of relatively sharp fluorescent lines, covering the whole visible and near-infrared spectrum 380) search for new laser materials and investigations of the characteristics of laser emission at different temperatures of the active material and with various pump sources have improved knowledge about the solid state spectra and radiationless transitions in laser media 38i). 

It is characteristic of such a laser ion source that the experimental conditions for LIMS can be optimized with respect to a stoichiometric evaporation and effective ionization of solid sample material by varying the laser power density as demonstrated in Figure 2.20. Under certain experimental conditions fractionation effects can be avoided. Stoichiometric laser evaporation and ionization of analyzed material is found at a laser power density between 109Wcm 2 and 1010Wcm-2. In this laser power density range, the relative sensitivity coefficients of the chemical elements (RSC = measured element concentration/true element concentration) are nearly one for all the... 

The quantum yields of fluorescence of the different systems have also been determined relative to a single crystal of neodymium-doped YAG for which a quantum yield of unity has been assumed (Heller, 1968a). The quantum yields obtained, even if they are accurate only within a factor of two, follow the same trend as for the lifetimes, with the highest values for the acidic solutions 0.70 and >0.75 in presence of S11CI4 and SbCls, respectively. Neutral and basic solutions are less luminescent and have quantum yields of 0.5 and 0.4, respectively. Identical measurements performed on a sodium-compensated neodymium-doped calcium tungstate crystal lead to a value of 0.5. The high quantum efficiency and the low threshold (between 2 and 40 J) of these Nd3+ SeOCl2 systems clearly demonstrate that liquids are not inherently inferior to solids as laser materials. 

The non-relativistic version of DVME method was developed in 1998 and was applied to the analysis of multiplet spectra of ruby [6-8]. This method was later applied to the analysis of a variety of TM-doped solid-state-laser materials [9-11]. The relativistic version of DVME method was developed in 2000. However, at that time, it was still difficult to calculate multiplet spectra of RE ions due to the limited performance of available computers. On the other hand, the relativistic... 

Where Avbw is the total oscillating bandwidth. The shortest pulses are therefore generated by the widest frequency distributions, that is, by arranging for a broad gain bandwidth. Only those frequencies in the emission spectrum of the laser material that can be maintained above the lasing threshold will participate in Avbw Dye lasers and some solid-state lasers (titanium-sapphire) have broad spectral outputs and can produce pulse widths significantly lower than 1 ps. Gas lasers have much narrower bandwidths and typically have pulse widths closer to 100 ps. The solid-state Nd YAG laser is intermediate at near 30 ps. 

Although LA is too expensive to be the method of choice for solution analysis, the use of synthetic solutions and dual sample insertion systems for laser-induced aerosols mixed with liquids (dried and wet) has offset the lack of solid reference materials for quantitation [14,45 8,55]. A specific sample preparation procedure exists [118] for... 

The LIBS technique basically involves four steps, namely laser-solid interaction, material removal, plasma formation (also called breakdown ) and analysis of the photons emitted by the plasma formed. The conditions used in each step are usually optimized in relation to the particular application. Two of the previous steps (viz. laser-solid interaction and material removal) are also present in laser ablation (see Section 9.2.2). 

R.C. Powell, Physics of Solid-State Laser Materials (Springer, New York, 1997)... 

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