The samples of well-oxidized REBa2Cu3O7-δ with different trivalent RE (rare earth) ions, were studied with use of EPR method at the temperature above of liquid nitrogen (77 K). The measured samples were obtained by the solid phase synthesis method. The aim of these measurements was to find and describe the relation between critical temperature, critical magnetic field, and the shape of the resonance signal. It was expected that samples possess the HTSC transition at about 90 K. For most samples, both a nonresonant absorption and emerging of HTSC state were visible in the EPR experiment. The evolution of these signals allowed determining the critical temperature, as well as the evolution of the critical magnetic fields as a function of temperature. Additionally, EPR signal of Cu (II) ions was detected and explained by insufficiently oxidized samples or the existence of contaminated phases.
Cobalt doped La3Ga5.5Ta0.5O14 single crystal (0.5 mol.% in the melt with respect to Ga) grown by the Czochralski method has been investigated using electron paramagnetic resonance and optical absorption measurements. X- band EPR spectra observed at 8 K under rotation around c crystal axis consists of two asymmetric lines: a narrow line at ~150 mT magnetic field and a second wider line at ~350 mT. These lines could be ascribed to the high spin S=3/2 Co2+ ions located at two different crystallographic positions. The low field signal arises from cobalt occupying Ga positions with C3 symmetry (octaheder), whereas dominating in spectrum, more complicated signal at higher fields arises from cobalt located at Ga positions (tetraheder) with C2 point symmetry. The whole spectrum repeats every 60° as is expected for trigonal crystal symmetry. Optical measurements have confirmed the conclusion especially for γ-irradiated crystals which reveal additional Co3+ content after the treatment. Co3+ ions are also seen in "as-grown" (not irradiated) crystals as 5T2-5E transition giving absorption bands in the range 700-1100 nm. So in the "as-grown" crystals there arise Co2+ ions at octahedral or tetrahedral Ga sites and Co3+ ions at octahedral Ga sites.
Electron paramagnetic resonance spectra of La3Ga5.5Ta0.5O14:Ho single crystal for the presence of Yb3+ magnetic nonequivalent centers are analyzed. Centers of different symmetries we found two of which being cubic symmetry sites. The existence of the cubic symmetry centers of the Yb3+ ions in LGT host crystal confirm that Yb3+ ions occupies eightfold coordinated La3+ ions. The values of the g-factor for these centers are estimated as: g = 2.059 ± 0.004 (I centre) and g = 2.840 ± 0.015 (II centre). Some results of optical measurements are also presented. They indicate sharp but a weak Yb3+ absorption centered at about 978 nm in the IR part of the absorption spectrum, and, equally weak Ho3+ absorption in the UV-VIS part of the spectrum (fundamental absorption edge being equal to 250 nm). We think Ho and Yb ions compete in substituting of lattice sites in the crystal. Photoluminescence measurements have shown a very strong signal in the green (533 - 555 nm), slightly less in red (637 - 671 nm) and near-IR (735 - 769 nm) spectral ranges. Co-activation of the Yb-doped crystals with holmium ions leads to appearance of visible luminescence, which is explained by the Yb3+-Ho3+ stepwise up-conversion mechanism. Additional absorption measurements performed after γ-irradiation with a dose of 105 Gy show wide band originating at 250 nm and extending up to 500 nm (probably due to recharged cation and oxygen vacancies) for both LGT pure and LGT:Yb, Ho single crystals, the lowering of the amount of Yb3+ and Ho3+ ions (due to Compton electrons capture) and additional absorption band centered at about 600 nm (charge compensating defects) for LGT:Yb, Ho single crystals. Thermoluminescence measurements (TL), does not reveal the presence of any traps in the TL glow curve.
Electron paramagnetic resonance (EPR) measurements of LiNbO3: Yb, Pr (0.8wt.%, 0.1 wt.%) single crystals were analyzed for lattice sites of Yb in the crystal and also for the Yb3+ pairs arising. Parameters of the spin Hamiltonian were calculated using EPRNMR program. From the angular variations of the EPR spectra it results Yb3+ ions of C1 symmetry arise in the crystal. Pr3+ ions change parameters of spin hamiltonian for Yb3+ ion. Some results of the absorption measurements were also analyzed for UV-VIS and IR giving evidence, together with EPR results, on Yb3+ location at Li+ sites and Pr3+ location at Nb5+ sites. For comparison absorption spectra of the LiNbO3 doped with 0.5 wt. % Pr3+, 0.8 wt. % Yb3+ were analyzed. Low temperature absorption measurements have shown the presence of low energy phonons responsible for the intensity of the main Yb3+ absorption line in IR as a function of the temperature. Raman spectra confirmed the observation.
Electron paramagnetic resonance (EPR) measurements of CaF2:Yb (5 mol. %) single crystals were performed for lattice sites substituted by Yb ions and also for the possibility of Yb3+ pairs arising. Among eight lines observed in the EPR spectrum, with g = 4.293, 4.1, 3.965, 3.665, 3.433, 3.13, 3.054, 2.894 we think mainly the lines coming from different isotopes of Yb3+ isolated ions of cubic symmetry one can distinguish: 170Yb3+ I=0, 171Yb3+ I=1/2 and 173Yb3+ I=5/2, but one can not exclude the lines coming from Yb3+ pairs. All of the lines have got an axial symmetry along the crystallographic axis, since the lines do not move with angular variation in the planes parallel and perpendicular to the axis. One can observe also the extra line in magnetic field orientation in every plane at 45°, with the B0≈191 mT. The unidentified line corresponds to non-axial Yb3+ center or unknown impurity. The components of A and g tensors of the spin Hamiltonian for cubic symmetry were calculated. Temperature dependence of EPR lines shows agreement with the Curie law for most of the lines. Peak-to-peak linewidth changes continuously within 20 mT range for "as-grown" crystals, while shows distinct increase above 25 K for γ-irradiated ones. It suggests strong ferromagnetic coupling between neighbours Yb3+ and Yb2+ ions the latter being created due to Compton electron capture. So, Yb3+ co-exists with Yb2+ after the Yb3+-Yb2+ conversion under influence of γ-irradiation and/or annealing in hydrogen. It seems the Yb2+ centers arising in CaF2:Yb (5 mol. %) single crystal after γ-irradiation are related to Yb3+, as an effect of recharging one of Yb3+ ion from a pair. Absorption measurements of CaF2 highly doped with Yb3+ (0.5 mol. %, 5 mol. % and 30 mol. %) reveal the shifting of the IR maxima of 921 and 980 nm characteristic for 0.5 mol. % doping of Yb3+ towards the centrum of IR band (927 and 976 for 30 mol. % of Yb3+). Raman spectrum shows localized phonon centered at about 64 cm-1 being confirmation of the Yb3+ pairs presence in the 5 mol. % of Yb3+ doped CaF2 crystal.
Optical homogeneity (birefringence and birefringence dispersion mapping, transmission and additional absorption) was investigated on the entire areas of LiNbO3 wafers doped with Cu ions and irradiated with protons of fluencies ranging between 1012 and 1016 cm-2. The birefringence dispersion studies have revealed a considerable influence of protons on LiNbO3:Cu optical inhomogeneity, whereas the same influence on undoped LiNb03 was much less significant. The spectroscopic studies have revealed different mechanisms of defect formation depending on doses of protons. Also the secondary electrons generated by proton irradiation are believed to decrease the optical homogeneity by decreasing crystal's conductivity and generation of the color centers.
In the absorption spectrum of the crystal there was stated the presence of Ti3+ ions at octahedral Ga positions in strong crystal field. Ti3+ ions arise due to some reducing conditions of the crystal growth. It was found that electron delocalization at higher temperature, e.g. In oxidation-reduction reaction: Ti4+ + e equals Ti3+ may appear in optical spectra as charge transfer bands in the NIR region giving rise to blue absorption. The observed fluorescence of 2T2-2E transition of Ti3+ in the LaGaO3/SrTiO3 mixed crystals shows two bands centered at about 420 and 447 nm coming from excitation at 314, 340 and 384 nm.
Cobalt doped SrLaGa3O7 single crystals have been grown by the Czochralski method in a nitrogen atmosphere and by a floating zone method with optical heating in air. Starting concentrations of Co in the melt were: 0.15, 0.3, 2 and 3 mol percent with respect to Ga by the Czochralski method whereas 2 and 4 mol percent by the floating zone method. We have presented absorption spectra as well as EPR spectra related to octahedrally coordinated Co2+ ion in SrLaGa3O7.
An interesting phenomenon of thermal annealing in gamma irradiated undoped, and photorefractive Cu- and Fe-doped, Z- oriented LiNbO3 crystal has been observed. Prior and after each gamma irradiation the crystals were thermally annealed in the air at 800 degrees C for a couple of hours. Optical homogeneity was investigated on the entire area of LiNbO3 wafers by measuring distributions of birefringence, the principal azimuth, transmission, and parameters associated with birefringence dispersion, and also by measurements of additional absorption in a few wafers' points. It has been rather unexpectedly observed that the classical thermal annealing can lead to a decease in optical homogeneity in the majority of cases. It is attributed to generation of an internal electric field by the pyroelectric effect, and to the electrooptic effect involved thereafter. On the other hand, the secondary electrons generated by gamma irradiation are believed to increase the optical homogeneity by increasing the crystal's conductivity and dissipating this field. A uniform temperature heating across the wafer generated by this irradiation is also a helpful factor in this gamma- annealing. It has been found that this effect at room temperature by this irradiation is also a helpful factor in this gamma-annealing. It has been found that this effect at room temperature is small for gamma irradiation of 105 Gy, while increasing the doses to 106 Gy and 107 Gy can profile in a considerable reduction of the optical inhomogeneity. A certain influence of Cu-doping on this effect has also been observed.
In this paper changes in active and lattice ions valence were investigated in some laser materials such as: Cr:Y3Al5O12, Cr:LiNbO3 and Cr:Li2B4O7 glass, Ti:Al2O3 and Ti:LaGaO3, Co:SrLaGa3O7 and Co:Li2B4$?O(subscript 7 glass, Eu, Dy:Li2B4O7 glass, Ho:LiTaO3, Nd:YVO4 , Nd:SrLaGa3O7 and Pr:SrLaGa3O7 after annealing in oxidization and reducing atmospheres, ionizing with gamma, electrons and protons. After (gamma) -irradiation 446 nm emission is observed for Ti:LaGaO3 single crystal due to 2E yields 2T2 transition of Ti3+.
Absorption and emission spectra of Cr, Eu and Dy ions in Li2B4O7 glasses melted in oxygen and hydrogen were measured for valency states and excited states analysis. It was stated that the presence of Cr6+ ion is limited by composition of the starting mixture and atmosphere of the melting and that this ions arises as Cr6+O4 complex.
Results of phase transition investigations of Nd:YVO4 single crystal to Nd:YVO4 single crystal in hydrogen at 1200 degrees C for 1h were presented. The refined lattice parameters obtained for the latter case, a0 equals 5.2858(1) angstrom, b0 equals 5.5956(2) angstrom and c0 equals 7.5854(2) angstrom, are slightly larger only than those of YVO3. Valency change was also investigated of Cr ions due to transition in Cr4+:Y3Al5O12 and Cr3+:SrLaGa3O7 Ho and Pr ions in LiTaO3 and Co3+ due to transition in LaGaO3 single crystals under influence of annealing in reducing and oxidizing atmospheres and gamma and proton irradiations.
Results of absorption and radio luminescence measurements of YalO3, Y3Al5O12, LiTaO3, LiNbO3, YVO4 single crystals and Li2B4O7 single crystals and glasses doped with rare-earth and transition metal ions and LiF crystal were presented. Analysis of excitation energy transfer of x-rays from lattice sites to active ions was performed. Changes in absorption spectra were also analyzed due to (gamma) -quanta irradiation of Nd3+ doped LiYF4 single crystal with a dose of 105 Gy.
Slawomir Kaczmarek, Andrzej Wojtowicz, Winicjusz Drozdowski, Czeslaw Koepke, Krzysztof Wisniewski, Jaroslaw Kisielewski, Ryszard Jablonski, Marek Grinberg, Justyna Barzowska, Benedykt Kuklinski, Georg Zimmerer, Zbigniew Moroz, Henryk Rzewuski
Absorption, luminescence, ESR and ESA spectra and TL glow curves of YAG:Ce crystals codoped with Mg2+ ions and subjected to various treatments have been measured. The variations induced by irradiations in gamma and proton beams, and by thermal annealings under oxidation and reduction conditions point to large variations of the cerium ion valency. The ESA spectra of Mg-free and Mg-codoped crystals are clearly different with the peak value in the YAG:Ce, Mg sample higher and shifted towards the shorter wavelengths. Although the TL glow curves reveal the existence of the same major traps in both materials, their role in the overall deexcitation process is strongly modified upon Mg-codoping.
Growth conditions for Nd:YVO4 crystals and some optical properties are presented. The obtained Nd:YVO4 crystal shows lower content of point defects and consequently, lower susceptibility to ionizing radiation. ESR measurements show the presence of V ions in interstitial sites with another than 5t valency. Obtained by Czochralski method crystals reveal very good optical properties, some of which are better than for Nd:YAG.
Electron Spin Resonance and optical absorption spectra of trivalent vanadium in Y3Al5O12 crystals before and after (gamma) -irradiation and thermal annealing treatments are reported. The observed spectra are interpreted as arising from octahedrally coordinated V3+(3d2) ions. We obtained Lande factor 2gx equals 2.237, and hyperfine structure constant A(parallel) equals 330 X 10-4 cm-1 for T equals 4 K. It is possible to obtain tetrahedrally coordinated V3+ ions using annealing of YAG:V crystal in reducing atmosphere.
An analysis of actual state of a view about pulsed laser deposition method, its applications and perspectives and also physical phenomena during laser deposition processing were presented.
Excitation-mission spectra have been measured for Pr3+, Ce3+, Nd3+ and Eu3+ doped YAP, YAG, and SLGO crystals in room temperature. Results of additional absorption measurements and changes in a luminescence after gamma irradiation with dose up to 105 Gy and energy of 2.5 MeV are also presented.
'Eye safe' lasers are very important for different applications in optical communication and lidar techniques. In this work we report the results of measurements of generation characteristics of Nd:GGG, Nd:YAG crystals for wavelength of 1.32 micrometer as well as Nd:YAP crystals generating radiation of 1.34 micrometer. Influence of UV radiation on the output characteristic of Nd:GGG laser is also reported.
The results of investigations of gamma radiation influence on laser performance of Nd:SLGO, Er:YAG and CTH:YAG crystals were reported. Twice and fourfold increase of optical output was stated for Er:YAG and Nd:SLGO, CTH:YAG lasers, respectively. The increase takes place due to color centers created by gamma quanta, that is due to additional absorption bands appearing in the crystals after gamma irradiation.
The results of spectroscopic investigations of YAP-Er (50 at %) single crystals at temperature T equals 50 K are presented in this work. The influence of (gamma) -irradiation and thermal annealing on optical properties of YAP-Er is studied.
Gamma-induced transition of Ce4+ $ARLR Ce3+ was investigated for Ce,Nd:YAG samples cut off from the same crystal and differing one to another by a few tenth percent of Ce3+ ions concentration (starting concentration). Depending on the starting concentration changes of resulting concentration of Ce3+ ions were observed. The luminescence of Ce,Nd:YAG crystal at about 530 nm increased independently on Ce3+ starting concentration.
Single crystals of SrLaGa3O7 doped with 0.5 and 1 at.% praseodymium were grown by the Czochralski technique. A heating system with good thermal insulation and afterheater were applied in order to achieve appropriate radial and axial temperature gradients in the crystallization chamber. Low temperature gradients and flat crystal-melt interface could provide good optical quality crystals free of internal stresses. All single crystals were grown in [001] direction. The pulling rate was 1.5 - 3 mm/h and the rotation rate 50 rpm. The composition and dopant's distribution in crystals were checked by x-ray microprobe. The obtained crystals up to 25 mm in diameter and up to 80 mm in length were of good quality and the dopant's distribution was uniform. The doped crystals were investigated for their spectral an lasing properties. Absorption spectra in range of 180 - 8000 nm were measured, then laser rods were cut out and their generation properties were evaluated.
The influence of gamma and electron irradiation on optical and lasing properties of Y3Al5O12, Gd3Ga5O12, YAlO3 and LiNbO3 single crystals doped with rare-earth ions was studied. The laser output energy in the Nd-doped laser crystals and (gamma) -irradiation is decreased due to passive losses on the laser generation wavelength 1.06 micrometer (reabsorption of the laser radiation by color centers). The color centers in YAG-Er crystals may fulfill the sensibilizator function providing an increase of the pumping efficiency and output energy of the laser generation at 2.94 micrometer.
In this work the optical and lasing features of 1.2at. percent neodymium doped GGG crystals in comparison to YAG, SLGO and YAP ones are presented. Influence of UV and gamma radiations on a change of absorption and luminescence spectra of the crystal is also reported. The strong influence of UV radiation of pump lamp on lasing characteristics of GGG:Nd crystals is stated. After cut off UV from pump lamp spectrum the slope efficiency of GGG:Nd laser can be placed between SLGO:Nd and SLGO ones.
In the present work the effects of gamma radiation on optical characteristics of Nd:SrLaGa3O7 crystals and results of examinations of lasing characteristics of gamma irradiated active elements made from the above crystals are reported. The increase of optical output was established for 'bad' rod. The possible mechanisms of radiation influence are discussed.
The paper regards both the effects of gamma radiation on optical characteristics of YAG:Er, YAG:CTH crystals and examinations of generation characteristics of active elements made from the above mentioned crystals irradiated with gamma quanta as well.
Investigations of spectroscopic properties of yttrium-aluminium garnet Y3Al5O12 (YAG) doped with Ce, Pr, Nd, Sm, Eu, Ho, Er, Tm, Yb ions and Nd:YAG, Nd:SrLaGa3O7, Nd:SrLaAlO4, Nd:YVO4, Nd:LiYF4, Nd:PbMoO4, Nd:LGS, Nd:GGG, Nd:SVAP monocrystals have been realized. Absorption spectra of the monocrystals in the range 200 nm divided by 20 micrometers and the luminescence spectra in the range 200 divided by 800 nm were determined. Except for Pr:YAG, Sm:YAG, Eu:YAG and Pr,Yb:YAG in all other materials an appearance of strong absorption bands in the range of 780 divided by 840 nm has been stated what enabled to carry out an efficiency analysis of selective pumping with the use of GaAlAs laser diodes.
Examined praseodymium doped crystals with 1 at.% of Pr3+ ions for YAG and SrLaGa3O7 (SLGO) hosts were produced using Czochralski method. The luminescence for the range of 200 - 800 nm and absorption spectra for a wide range of 200 - 6000 nm, for Pr3+:YAG and Pr3+:SLGO crystals have been measured. It was stated that for praseodymium doped YAG and SLGO crystals, the strongest peaks of luminescence occur at 0.489 and 0.502 micrometers and the strongest peaks of absorption occur at 0.44 - 0.5 and 0.58 - 0.62 micrometers bands. A free-running laser emission of (lambda) equals 0.62 micrometers radiation for both types of crystals Pr:YAG and Pr:SLGO for two different transmissions of output mirrors have been obtained.
Investigations of spectroscopic properties of yttrium-aluminum garnet Y3Al5O12 (YAG) doped with Ce, Pr, Nd, Sm, Eu, Ho, Er, Tm, Yb ions and Nd:YAP, Nd:SrLaGa3O7, Nd:SrLaAlO4, Nd:YVO4, Nd:LiYF4, Nd:PbMoO4, Nd:LGS, Nd:GGG, Nd:SVAP monocrystals have been realized. Absorption spectra of the monocrystals in the range 200 nm - 20 micrometer and the luminescence spectra in the range 200 - 800 nm for Pr:YAG, Pr:YAP and Pr:SrLaGa3O7 were determined. Except for Pr:YAG, Sm:YAG, Eu:YAG and Pr,Yb:YAG in all other materials an appearance of strong absorption bands in the range of 780 - 840 nm has been stated that enabled us to carry out an efficiency analysis of selective pumping with the use of GaAlAs laser diodes.
SLAO crystals were grown from the melt by the Czochralski method. Undoped and doped with neodymium up to 5 at.% SLAO single crystals of [100] orientation were obtained. The optical transmission characteristics within the wavelength range of 190 - 7400 nm for undoped and Nd-doped crystals were measured. The results of ESR measurements in the temperature range 70 K to 4 K are also presented.
Single crystals of SrLaGa3O7 undoped and doped with 5 and 10 at.% of neodymium were grown by the Czochralski technique. These crystals were investigated for their spectral properties. Absorption spectra in the range of 180 - 8000 nm were measured. Throughout the whole spectrum differential changes of the absorption were found. Optical transitions corresponding to this effect are indicated. The Nd-doped crystals were investigated for their lasing properties in the free-running generation.
Investigation of spectroscopic properties of yttrium-aluminum garnet Y3Al5O12 (YAG) doped with ions of rare-earth elements Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Ho3+, Er3+, Tm3+, Yb3+ monocrystals yttrium-aluminum perovskite YAlO3 (YAP), SrLaGa3O7 (SLGO) and SrLaAlO4 (SLAO) doped with Nd3+, and LiNbO3 doped with Er3+ and Tm3+ obtained by the Czochralski method have been realized. Absorption spectra of the monocrystals were determined in the range 200 nm divided by 20 micrometers as well as luminescence spectra in the range 200 divided by 800 nm. Research works enabled to estimate spectroscopic properties of these materials as active media for solid state lasers. Except for YAG:Pr3+, YAG:Sm3+, YAG:Eu3+ and YAG:Pr3+,Yb3+ in all other materials an appearance of strong absorption bands in the range 780 divided by 840 nm has been stated what enabled to carry out an efficiency analysis of selective pumping with the use of laser diodes GaAlAs.
The method of preparation and conditions of SrLaAlO4 (SLAO) single crystal growth are presented. Undoped and doped with neodymium up to 5 at% SLA single crystal of [100] orientation were obtained and tested. The optical transmission characteristics within the wavelength range of 300 - 8300 nm for Nd-doped crystals were measured. The high absorption coefficient of 5 at% Nd doped SLAO single crystals in the 805 - 810 nm band, characteristic for laser diode pumping were observed.
In this paper the theoretical model for laser cutting, welding, hardening and alloying was shown. It was stated that the boundary problems for heat transfer equation in the range of material layer with finite thickness for moving laser source. It was carrying out the nondimensional analysis, where the problem solution was stated by three dimensionless parameters.
Miniature solid state lasers were built using new active crystals (Nd:SrLaGa3O7, Cr, Tm, Ho:YAG, Er:YAG). Output power is equal to 30 - 40 mJ and threshold pump power of 60 - 70 J has been obtained for Cr, Tm, Ho:YAG and Er:YAG lasers.
This paper presents research results on color centers induced by radiation of a xenon lamp in non doped crystals of yttrium aluminum garnet Y3Al5O12 (YAG), strontium- lanthanum aluminate SrLaAlO4 (SLAO), strontium-lanthanum gallate SrLaGa3O7 (SLGO), and in doped crystals: Nd:YAG, Cr, Tm, Ho:YAG (CTH:YAG), Nd:SLAO and Nd:SLGO. In all these investigated crystals under the influence of intensive exposure by xenon lamp radiation additional bands connected with centers O-2, O2 and centers F came up near the short-wave absorption edge. In the case of doped crystals the observed processes are much more complicated. In crystals CTH:YAG the greatest perturbations in relation to basic state are present at the short-wave absorption edge, as well as on areas of absorption bands of ions Cr+3 and Tm+3 conditioning the sensibilization process of ions Ho+3. These spectral structure disturbances essentially influence the efficiency of this process, as proven during generating investigations. In the case of SrLaGa3O7:Nd+3 under the influence of exposure substantial changes of absorption spectrum occurred on spectral areas 346 divided by 368 nm, 429 divided by 441 nm and 450 divided by 490 nm. Those changes have an irreversible character. They disappear not before the plate is being held at oxidizing atmosphere. Investigations of laser rods Nd:SLGO, CTH:YAG, and Nd:YAG in a free generation demonstrated that the color centers of these crystals are induced by pomp radiation from the spectral area up to 450 nm.
Czochralski-grown Nd-doped SrLaGa3O7:Nd (SLGO) crystals have been investigated for their lasing and spectral properties. Absorption spectra in the range of 180 - 8000 nm and the luminescence spectra in the range of 200 - 800 nm were measured. Differential changes of the absorption coefficient were investigated throughout the whole spectrum. Optical transitions corresponding to this effect have been indicated.
Comparative research works on spectral characteristics of monocrystals of Y3Al5O12 doped with ions of rare-earth elements Pr3+, Nd3+, Eu3+, Ho3+, Er3+, Tm3+, monocrystals SrLaGa3O7 and SrLaAlO4, doped with Nd3+, and LiNbO3 doped with Er3+ obtained by the Czochralski method have been realized. Absorption spectra of these monocrystals have been determined in the range 200 nm divided by 20 micrometers and spectra of excitation and emission in the range 200 divided by 800 nm. Research works enabled us to estimate spectroscopic properties of these materials as active media on solid. Except for YAG:Eu+3 and LiNbO3:Er+3 in all other materials an appearance of strong absorption bands in the range 780 divided by 840 nm has been stated as what enabled us to carry out an efficiency analysis of selective pumping with the use of laser diodes GaAlAs.
An analysis has been carried out of the time characteristics of the laser cutting process resulting from the solution of heat conductivity equation inside the steel sheet on heat sources (laser beam) inside that sheet. It is assumed that laser beam has a Gaussian spatial shape. The heat conductivity equation and boundary conditions have been derived for a 3D sheet which moves with a constant velocity v towards x direction. Results obtained were compared to solutions of quasistationary equation referring to the same problem.
Fluorescence profiles were measured together with water samples taken in three expeditions to Norwegian Sea between 1988 and 1991. Chlorophyll concentration values obtained for the samples with a spectrophotometric method were used to recalibrate the fluorescence profiles to chlorophyll units.
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