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Construction of 879?nm direct intra-cavity pumped dual-wavelength laser operating at 912?nm and 1064?nm
摘要： A dual-wavelength continuous-wave laser with direct intra-cavity pumping using a 879 nm laser diode that utilizes Nd:GdVO4 and Nd:YVO4 crystals, is presented. To the best of our knowledge, this system completely eliminates the gain competition between the 912 nm and 1064 nm transitions for the first time. A theoretical model is introduced to describe this intra-cavity pumped dual-wavelength laser. The lasing threshold of the 912 nm Nd:GdVO4 laser is presented by considering the ground-state reabsorption loss effect. A total output power of 1.33 W at dual-wavelength operation with an absorbed pump power of 7.91 W is experimentally achieved. The individual output power for the 912 nm and 1064 nm emissions were 0.43 W and 0.9 W, respectively. Both wavelengths operate in TEM00 mode with a total slope efficiency > 20%.
关键词： Lasers,Neodymium,Dual-wavelength,Solid-state,Intra-cavity pumped
更新于2025-11-28 14:23:57
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Solvent-Dependent Sensitization of Ytterbium and Neodymium via an Intramolecular Excimer
摘要： We report the synthesis of a di(1-pyrenyl)-phosphoryl acetophenone ligand containing two pyrenyl moieties linked by a single phosphorus atom. The ligand exhibits solvent-dependent emission: in nonpolar solvents, typical monomeric pyrene emission is observed, whereas in polar solvents, an additional broad and structureless emission appears. The emission in polar solvents is concentration independent and is attributed to the emission of an intramolecular excimer. The coordination of the di(1-pyrenyl)phosphoryl acetophenone ligand as well as the corresponding deprotonated anionic di(1-pyrenyl)phosphoryl acetophenonate ligand was studied with the near-infrared emitting lanthanides, neodymium and ytterbium. Solvent-dependent sensitization of both lanthanides was observed and correlates with the presence of the excimer emission. Sensitization of ytterbium is more efficient than neodymium, and the overall quantum yields were found to be 12.8 and 1.9% for ytterbium and neodymium, respectively.
关键词： solvent-dependent emission,quantum yields,ytterbium,neodymium,intramolecular excimer,lanthanides
更新于2025-11-14 15:24:45
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External irradiation with heavy ions of neodymium silicate apatite ceramics and glass-ceramics
摘要： This work aims at comparing the damage induced in the Nd silicate apatite ceramic (Ca2Nd8(SiO4)6O2) by medium energy (ME) and swift heavy ion (SHI) irradiations to evaluate the effects of nuclear collisions and intense electronic excitations for ME ions and SHI ions respectively. The macroscopic induced changes were studied as a function of the fluence by swelling and hardness measurements, whereas structural modifications were followed by X-ray diffraction, Raman spectroscopy and grazing incidence EXAFS (Nd L3-edge). At ME (1.9e6.75 MeV Au ions), radiation-induced amorphization occurred above 6.22 (cid:1) 1013 Au/cm2 associated with a volume expansion of about 8% and a drop of 37% in hardness. At SHI (90 MeV Xe ions or 35 MeV Ar ions), similar macroscopic and structural changes were observed. The electronic stopping power threshold of Nd silicate apatite for amorphization was assessed at about Se ? 5 keV/nm. As apatite crystals containing actinides could be present in rare-earths rich nuclear glasses, SHI irradiation with Xe (995 MeV) ions was also used to damage the Nd silicate apatite crystals dispersed in a soda-lime aluminoborosilicate simplified nuclear glass over a depth of about 60 mm, to evaluate the possible formation of cracks in the residual glass due to crystals swelling. In spite of apatite crystals amorphization under SHI irradiation in the glass-ceramics, no cracking was observed in the glassy phase even close to the biggest crystals which could be explained by strain relaxation in the glass due to plastic deformation (creep) induced by SHI ion beam.
关键词： Amorphization,Glass-ceramic,Neodymium silicate apatite,Heavy ions irradiation
更新于2025-09-23 15:23:52
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Structural, optical and magnetic elucidation of co-doped of Nd+3 and Pr+3 on lithium nanoferrites and its technological application
摘要： LiNiCo spinel ferrites were prepared, by doping with rare earth metals Nd and Pr, according to micro-emulsion method. In order to study the effect of Nd and Pr, the crystal structure and magnetic properties of prepared ferrites were scrutinized in detail. The endorsement of single-phase spinel ferrites with the co-occurrence of orthophase was confirmed by XRD and FTIR. The average crystallite size varied with increasing the doped concentration of Nd and Pr, which is in the range from 28nm to 70nm. Magnetic properties were analyzed by VSM within range of -10000Oe and 10000Oe. MS and MR values decreased with the increase in concentration. The value of HC, MR, and MS showed stability for transformer core where electromagnetic interference is reduced. Hence synthesized ferrites LiNi0.35-yCo0.15PryNdxFe2-xO4 are suitable for transformers and induction.
关键词： Microemulsion,XRD,Li-Pr,Neodymium,Nanocrystalline ferrites,Praseodymium,Magnetic properties
更新于2025-09-23 15:23:52
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Equine Surgery || Lasers in Veterinary Surgery
摘要： Surgical lasers facilitate minimally invasive surgery, allow surgical access to otherwise inaccessible areas, and induce tissue interactions, which cannot be obtained with conventional surgical instrumentation. Surgical laser procedures can be performed on an outpatient basis and have eliminated procedures that previously required general anesthesia and hospitalization. Surgeons should be knowledgeable about which procedures can be accomplished with surgical lasers and which are better suited to conventional surgery. This chapter will provide information and guidelines on the use of surgical lasers in equine surgery.
关键词： equine surgery,minimally invasive surgery,carbon dioxide laser,Surgical lasers,neodymium:yttrium-aluminum-garnet laser,holmium:yttrium-aluminum-garnet laser,diode laser
更新于2025-09-23 15:21:01
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Interactive tissue reactions of 1064a??nm focused picoseconda??domain laser and dermal cohesive polydensified matrix hyaluronic acid treatment in in vivo rat skin
摘要： Background: Picosecond-domain laser treatment using a microlens array (MLA) or a diffractive optical element (DOE) generates micro-injury zones in the epidermis and upper dermis. Objective: To investigate interactive tissue reactions between MLA-type picosecond laser pulses and cohesive polydensified matrix hyaluronic acid (CPMHA) filler in the dermis. Methods: In vivo rats with or without CPMHA pretreatment were treated with a 1064-nm picosecond-domain neodymium:yttrium-aluminum-garnet (Nd:YAG) laser using an MLA or DOE. Skin samples were obtained at post-treatment days 1, 10, and 21 and histologically and immunohistochemically analyzed. Results: Picosecond-domain Nd:YAG laser treatment with an MLA-type or a DOE-type handpiece generated fractionated zones of pseudo-cystic cavitation along the lower epidermis and/or upper papillary dermis at Day 1. At Day 21, epidermal thickness, dermal fibroblasts, and collagen fibers had increased. Compared to CPMHA-untreated rats, rats pretreated with CPMHA showed marked increases in fibroblasts and collagen fibers in the papillary dermis. Immunohistochemical staining for the hyaluronic acid receptor CD44 revealed that MLA-type picosecond laser treatment upregulated CD44 expression in the basilar epidermis and dermal fibroblasts. Conclusions: We suggest that the hyaluronic acid-rich environment associated with CPMHA treatment may enhance MLA-type picosecond-domain laser-induced tissue reactions in the epidermis and upper dermis.
关键词： laser,neodymium-doped yttrium aluminum garnet,cohesive polydensified matrix hyaluronic acid,laser-induced tissue breakdown,CD44,picosecond
更新于2025-09-23 15:19:57
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Thermo-optic and spectroscopic properties of Yb:GAGG, Nd:GAGG and Nd:GGG laser materials at cryogenic temperature
摘要： The solid-state lasers provide an attractive approach to enhance the laser performance benefitting from significant improvements in both thermo-optic and spectroscopic properties of the gain mediums under cryogenic temperature. Here, thermo-optic properties of Yb:Gd3(AlxGa1-x)5O12 (Yb:GAGG) and Nd:Gd3(AlxGa1-x)5O12 (Nd:GAGG) laser crystals, including thermal conductivity (κ), thermal expansion coefficient (α) and specific heat at constant pressure (Cp) were measured from 77 to 298 K. In addition, the thermal shock resistance parameters were also calculated. The spectroscopic properties and the fluorescence lifetimes of laser gain mediums Yb:GAGG, Nd:GAGG and Nd:Gd3Ga5O12 (Nd:GGG) were characterized at 77, 150, 298 K. The stimulated emission cross sections of these laser materials were determined by use of the Füchtbauer-Ladenburg (FL) formula at each temperature.
关键词： GGG,cryogenic cooling,GAGG,spectroscopic properties,thermal properties,Neodymium,Ytterbium
更新于2025-09-19 17:13:59
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On the Mechanism of Absorption and Restoration of Radiation Transmission in the Channel of Small-Scale Self-Focusing of a Short Laser Pulse in Neodymium Glass
摘要： When diagnosing a small-scale self-focusing (SSSF) channel of a 0.5-ns laser pulse with an intensity of 3–5 GW/cm2 in neodymium glasses, an absorption jump was detected (with a front of ≈0.5 ns) at wavelengths of 1.06 and 0.66 μ m in addition to filament-like damage typical of SSSF, spectral broadening, and laser radiation scattering. The absorption coefficient reached 0.15 cm–1, and transmission in the medium was restored during 15–35 ns for phosphate glass and 5–10 ns for silicate glass. The physical bases of this effect of the appearance and relaxation of absorption in glasses have not been previously presented. An analysis of the experimental data showed that the absorption jump is due to the fast population of the 4I11/2 level of Nd3+ ions in glasses when nonlinear processes occur in the SSSF channel such as stimulated Raman scattering and broadening of the laser pulse spectrum. The relaxation time of the population at the 4I11/2 level and the restoration of transmission in glasses after the termination of the laser pulse are determined by the characteristic sizes of the Nd3+ ions excitation regions arising in the samples upon interference of the laser and scattered radiation, as well as the thermophysical characteristics of the glasses.
关键词： self-focusing,neodymium glass,powerful laser pulse,induced absorption
更新于2025-09-16 10:30:52
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Luminescence study and Judd-Ofelt analysis of Nd 3+ doped lithium lanthanum borate glass for green laser device
摘要： Lithium lanthanum borated glasses doped with Nd3+ (LiLaBNd) were synthesized to study in luminescence properties and laser potential. Refractive index, density and molar volume of glass increase with increasing of Nd3+ concentration. Glasses absorb photon in visible light and near- infrared region corresponding to energy transition from 4I9/2 ground state of Nd3+. Covalent nature and interaction between Nd3+ and ligand result to small red shift of Nd3+ energy level. The strongest emission with 1059 nm corresponds to 4F3/2→4I11/2 transition of Nd3+ under 808 nm excitation. The optimum concentration of Nd2O3 for this glass is 0.50 mol% which creates the maximum intensity of emission. Luminescence decay curve indicated cross relaxation process between Nd3+with low probability and life time value as 114 microsecond for 0.50 mol% doped glass. Judd-Ofelt analysis was used to evaluate several radiative parameters. Narrow effective bandwidth, high stimulated emission cross section and branching ratio indicated the advantage potential to develop LiLaBNd glass for using as laser medium in green emitting laser device.
关键词： Luminescence,Borate glass,Neodymium
更新于2025-09-16 10:30:52
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Immediate effect of pulsed high-intensity neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on staphylococcus aureus and pseudomonas aeruginosa growth: an experimental study
摘要： The aim of this study was to evaluate the effect of pulsed high intensity neodymium-doped yttrium aluminum garnet (Nd: YAG) laser on staphylococcus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa) bacterial growth, which cause many health problems and establish which doses are effective in bacterial inhibition. Five samples of S. aureus and five samples of P. aeruginosa were prepared in the microbiology lab, one used as control sample and the other 4 samples acted as experimental samples. The experimental samples received pulsed high intensity Nd: YAG laser with a total dose of 500, 600, 700 and 800 joules. The primary measures are colony count and the percentage decrease in colony count, the colony count was assessed at baseline and after 24 h of laser application. There was significant decrease in colony count and the percentage decrease in colony count after pulsed high intensity Nd: YAG laser application in all experimental samples of S. aureus and P. aeruginosa after 24 h of application for all doses (500, 600, 700 and 800 j) as compared with the control sample, with the most effect in higher doses of pulsed high intensity Nd: YAG laser than lower doses in both types of bacteria. pulsed high intensity Nd: YAG laser was found to be an effective modality for inhibition of S. aureus and P. aeruginosa growth after a single application.
关键词： Bacterial growth,Pulsed high intensity neodymium-doped yttrium aluminum garnet (Nd: YAG) laser,Colony count
更新于2025-09-16 10:30:52