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Evaluation of the Efficacy of Erbium, Chromium-doped Yttrium, Scandium, Gallium, and Garnet Laser in Partial Pulpotomy in Permanent Immature Molars: A Randomized Controlled Trial
摘要： Introduction: The use of the erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser in vital pulp therapy contributes to the formation of dentin bridges and a sterile zone as well as the maintenance of the vitality of the pulp. However, no prior studies have used the Er,Cr:YSGG laser in partial pulpotomy of immature permanent teeth. The aim of this study was to compare the ef?cacy of partial pulpotomy treatment using mineral trioxide aggregate (MTA) alone and MTA with the Er,Cr:YSGG laser in permanent immature molars. Methods: A total of 90 caries-exposed permanent immature molar teeth were included and randomly divided into 2 groups: the MTA group (n 5 45) and the laser 1 MTA group (n 5 45). In the MTA group, MTA was applied to the exposed area on the pulp after bleeding control. In the same session, the tooth was restored with a composite resin. In the laser 1 MTA group, before MTA condensation, the Er,Cr:YSGG laser was applied to the exposure area. Patients were recalled at 1, 3, 6, and 12 months after treatment. The Mann-Whitney U and chi-Square tests were used for statistical analysis. Results: The success rate (95.5%) of the laser 1 MTA group was similar to that of the MTA group (88.8%). There was no signi?cant difference between groups in terms of the frequency of at least 1 pathologic clinical or radiographic failure at 12 months (P . .05). Conclusions: Partial pulpotomy treatment showed a high success rate in immature permanent molars; however, the use of the laser did not contribute to the success rate compared with MTA alone.
关键词： mineral trioxide aggregate,partial pulpotomy,Erbium, chromium-doped yttrium, scandium, gallium, and garnet laser,immature teeth
更新于2025-09-23 15:21:01
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Spin-wave excitation and critical angles in a hybrid photon-magnon-coupled system
摘要： We studied “strongly enhanced” excitations of magnetostatic spin-waves in a hybrid magnon-photon-coupled system consisting of an inverted split-ring resonator and an yttrium iron garnet film. The backward-volume magnetostatic wave, magnetostatic surface wave, forward-volume magnetostatic wave modes, as well as multiple mixed modes were observed according to the direction of externally applied magnetic fields with respect to the spin-wave propagation direction. From experimental measurements, we found that there exist certain characteristic angles, which is to say, critical angles (θc), whereby the group velocity of the excited spin-wave modes reaches zero, along with a single ferromagnetic resonance peak. Furthermore, we analytically derived the critical angles as sin θc = (Heff /H){2 ? (1 + μ0Ms/Heff )sin2 fc}1/2, where Heff is the effective magnetic-field strength, H the externally applied field strength, and μ0Ms is the saturation magnetization. This analytical form is in quantitative agreement with estimations from experimentally observed spin-wave modes. This work not only provides a better understanding of multiple-mode spin-wave excitations in given field directions with the help of photon-magnon coupling, but also offers better coupling controllability based on the change of the external magnetic field direction.
关键词： inverted split-ring resonator,critical angles,photon-magnon coupling,spin-wave,yttrium iron garnet
更新于2025-09-23 15:19:57
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Enhancement of magneto-optical properties in magnetic photonic crystal slab waveguide based on yttrium iron garnet
摘要： In this work, a polarization-independent waveguide based on magnetic photonic crystal (MPC) with a triangular lattice of air holes in Yttrium Iron Garnet (YIG) slab grown on alumina (Al2O3) substrate is proposed, where both TE-like and TM-like periodic band gaps overlap. YIG is well known for its attracting magneto-optical (MO) properties and used to produce a coupling between the TE and TM modes. Thus, a nonreciprocal effect can be obtained by applying an external magnetic field parallel to the direction of propagation. At 1550 nm, the complete photonic band gap is simulated and optimized using the three dimensional plane-wave expansion method. The aim of this study is to enhance Faraday rotation (FR) while maintaining a low modal birefringence. A numerical analysis in function of magnetic gyration (g) has been reported, using the BeamProp software. The results reveal a proportional relation between FR, ?n and g, such for g = 0.5, a large FR of 26.11×104 °/cm with ?n = 7×10–6. The results show a real improvement of this MPC structure based on YIG with larger FR, lower modal birefringence and minimal losses. The notable enhancement in the MO behaviour could improve the performance of optical isolators, and makes it suitable for nonreciprocal devices.
关键词： modal birefringence,magneto-optical properties,Yttrium Iron Garnet,Faraday rotation,magnetic photonic crystal
更新于2025-09-23 15:19:57
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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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Spin pumping and laser modulated inverse spin Hall effect in yttrium iron garnet/germanium heterojunctions
摘要： In this work, undoped semiconductors, germanium (Ge) and germanium tin (GeSn), were grown on ferrimagnetic insulator yttrium iron garnet (YIG) thin ?lms using ultra-high vacuum molecular beam epitaxy. The crystallinity of the structure was determined from x-ray diffraction and high-resolution transmission electron microscopy combined with energy dispersive x-ray spectroscopy. Both spin pumping and inverse spin Hall effects (ISHEs) of YIG/Ge and YIG/GeSn heterojunctions have been investigated with the help of broadband ferromagnetic resonance (FMR). We observe that the spin mixing conductances of YIG/Ge (60 nm) and YIG/GeSn (60 nm) are 5.4 (cid:2) 1018 m(cid:3)2 and 7.2 (cid:2) 1018 m(cid:3)2, respectively, responsible for giant spin current injection. Furthermore, it is found that spin pumping injects giant spin current from ferrimagnetic YIG into the Ge semiconductor. The infrared laser modulated ISHE was examined using heavy metal platinum as a spin current collector. Also, it has been noted that the variation in the power of laser irradiation signi?cantly changed the ISHE voltage of YIG/Ge/Pt spin junctions, saturated magnetization, FMR linewidth, and Gilbert damping parameter of YIG, which could be attributed to the laser-induced thermal effect. The outcomes from this study are promising for the development of Ge-based spintronic and magnonic devices.
关键词： germanium tin,magnonics,germanium,spin pumping,inverse spin Hall effect,yttrium iron garnet,spintronics
更新于2025-09-23 15:19:57
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Manipulation of the Size and Phase Composition of Yttrium Iron Garnet Nanoparticles by Pulsed Laser Post-Processing in Liquid
摘要： Modi?cation of the size and phase composition of magnetic oxide nanomaterials dispersed in liquids by laser synthesis and processing of colloids has high implications for applications in biomedicine, catalysis and for nanoparticle-polymer composites. Controlling these properties for ternary oxides, however, is challenging with typical additives like salts and ligands and can lead to unwanted byproducts and various phases. In our study, we demonstrate how additive-free pulsed laser post-processing (LPP) of colloidal yttrium iron oxide nanoparticles using high repetition rates and power at 355 nm laser wavelength can be used for phase transformation and phase puri?cation of the garnet structure by variation of the laser ?uence as well as the applied energy dose. Furthermore, LPP allows particle size modi?cation between 5 nm (ps laser) and 20 nm (ns laser) and signi?cant increase of the monodispersity. Resulting colloidal nanoparticles are investigated regarding their size, structure and temperature-dependent magnetic properties.
关键词： laser melting,yttrium iron oxide,monodisperse,laser fragmentation,phase transformation,garnet,perovskite,laser ablation,ferrimagnetic nanoparticles
更新于2025-09-23 15:19:57
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Magnetic linear birefringence of light in Tb3Ga5O12
摘要： The spectra of the magnetic linear birefringence (MLB) in the terbium-gallium garnet TbGG (Tb3Ga5O12) have been studied within the visible spectral range for temperature T = 90 K. Analysis of the temperature and spectral dependences of MLB has made it possible to determine the “e?ective” frequencies of the allowed →f d electric dipolar transitions in rare-earth (RE) ions of Tb3+ ions responsible for the formation of quadratic magneto-optical e?ect in this garnet. The results of the performed magneto-optical experiments in TbGG have con?rmed the Akulov's relations (for the quadratic magnetic e?ects) arising from the phenomenological consideration of MLB for the values of Δn measured at the orientation of the external ?eld in the plane (110) along the main crystallographic directions of the garnet crystal. From analysis of the experimental data on MLB was obtained that for the TbGG MLB changes quadratically with the ?eld within the temperature range 90–300 K. At the same time with a decrease in temperature, its value grows inversely proportional to the square of temperature. A certain di?erence was also found in the “e?ective" frequencies of the allowed transitions in Tb3+ ions of the garnet, which is determined from the optical absorption spectra of TbGG on the one hand, and from the analysis of the spectral dependence of MLD on the other one. It has been assumed that this di?erence can be due to signi?cant distortions of the TbGG crystal lattice caused by this signi?cant magnetostriction at low temperatures, leading to the "mixing" of the 9D term states with the "optically resolved" states of the 7D term.
关键词： Terbium-gallium garnet,Akulov's relation,Magnetic linear birefringence
更新于2025-09-19 17:15:36
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Temperature dependence of a garnet-type optical current sensor
摘要： A garnet-type optical current sensor (OCS) is studied. Ta/Nd2Fe14B/Ta groove ?lms are prepared on garnet by a magnetron sputtering method. The measurement errors of the Faraday rotation angle and the Verdet constant of the garnet-type and garnet-groove ?lm OCSs are measured by Thorlabs polarimeters as a function of temperature. The results show that the measurement errors of the Faraday rotation angle of the garnet-type and garnet-groove ?lm OCSs are 1.5% and 0.3%, respectively, when the current is 700 A at room temperature. The measurement error of the garnet-groove magnetic ?lm OCS is lower than 0.3%, when the current changes from 0 to 1000 A and the temperature changes from 25 °C to 80 °C. The Verdet constant variations of the garnet-type and garnet-groove ?lm OCSs cause di?erent measurement errors when the temperature is changed.
关键词： Measurement error,Temperature,Faraday e?ect,Garnet
更新于2025-09-19 17:15:36
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Crystallization of bismuth iron garnet thin films using capacitively coupled oxygen plasmas
摘要： It is demonstrated for the first time that amorphous bismuth iron garnet films can be crystallized within capacitively coupled oxygen plasmas at temperatures approximately 100 °C lower than required using conventional thermal annealing. We characterize the plasma optical emissions at high pressures (2 Torr–5 Torr) and high rf powers (500 W–800 W) and show that film crystallization is nevertheless related to thermal conditions generated in the plasma. It is demonstrated that these thermal conditions are related to the concentration of the dominant oxygen species O and O+ in the plasma, which, in turn, are a function of the rf power and pressure. The plasma treated garnet Faraday rotation and optical transmission are shown to be comparable with conventional oven or rapid thermal annealing.
关键词： capacitively coupled oxygen plasmas,thin films,bismuth iron garnet,Faraday rotation,crystallization
更新于2025-09-19 17:13:59
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Bound States in the Continuum in Magnetophotonic Metasurfaces
摘要： We analyze the enhancement mechanisms of magneto-optical effects in all-dielectric metasurfaces caused by the bound state in the continuum resonance. In a structure under study, a square lattice of bismuth substituted yttrium iron garnet nanodisks with an air hole displaced away from the disk axis, magneto-optical polarization and intensity effects reach 0.7° and 22%, respectively.
关键词： bound state in the continuum,magneto-optical effects,all-dielectric metasurfaces,bismuth substituted yttrium iron garnet
更新于2025-09-19 17:13:59