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We sought to assess the efficacy and safety of endovenous laser ablation utilizing a 980 nm device versus a 1470 nm device in the treatment of lower limb venous insufficiency. We performed a systematic review adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. A research on PubMed, Scopus and Web of science for articles published by January 2024 was conducted. The primary endpoint was great saphenous vein (GSV) and truncal vein occlusion. Eleven studies encompassing 3061 patients and 3193 truncal veins, were included. The 1470 nm device demonstrated superior truncal vein and GSV occlusion outcomes compared to the 980 nm device at the early, one-year, and medium to long-term follow-up intervals. Odds ratios (OR) were 2.79(95%CI:1.31–5.94), 2.22(95%CI:1.21–4.07), and 2.02(95%CI:1.24–3.29) for truncal veins and 2.54(95%CI:1.119–5.41), 2.06(95%CI:1.07–3.95) and 2.04(95%CI:1.25–3.33) for GSV, across the respective intervals. While both devices demonstrated minimal, deep vein thrombosis (DVT), endovenous heat-induced thrombosis (EHIT) ≥ 2, and burn estimates, the 1470 nm device exhibited improved paresthesia, risk ratio (RR), 0.51(95%CI:0.34–0.77) and pain outcomes, standardized mean difference (SMD), -0.62(95%CI:-0.99to-0.25). Subgroup analysis displayed enhanced occlusion outcomes with the 1470 nm device for the six-month and one-year intervals, irrespective of fiber type. Radial fibers were associated with improved paresthesia outcomes (β=-0.9520,p = 0.03). This review emphasized the enhanced efficacy of the 1470 nm device over the 980 nm device, regardless of fiber type. Radial fibers showed promise for improved paresthesia outcomes, suggesting similar safety profiles for both systems. Conclusive remarks on pain outcomes were impeded by data limitations. [ABSTRACT FROM AUTHOR]

The paper presents a simple and efficient Mode-Solver-based method for determining the ridge profile that ensures stable single-transverse-mode operation in ridge waveguide lasers. A quantitative figure of merit, easily derived from the Mode Solver analysis of the structure, indicates the likelihood of single transverse modal behavior over the whole bias range. The transverse mode analysis performed with the in-house developed software has been compared with the results of the commercial simulation package LASTIP and with experiments. The simulation and experimental results have been used to derive processing guidelines for achieving a stable single-transverse-mode operation in ridge waveguide lasers. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the LaOBr:Er3+ (0.1%) powders were prepared by solid state reaction. The structural properties of LaOBr:Er3+ were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. The results show that LaOBr:Er3+ has low phonon energy, which indicate that LaOBr:Er3+ may have high luminescent efficiency. Under excitation into 4I11/2 level of Er3+ ions by 980nm laser, the two- and three-photon upconverted luminescence of LaOBr:Er3+ were recorded. The most intense emissions were come from the 2H11/2, 4S3/2 → 4I15/2 transitions. The upconversion mechanisms were studied in detail through laser power dependence, and results show that excited state absorption is responsible for the upconversion. The upconversion properties indicate that LaOBr:Er3+ may be used in upconversion phosphors. [Copyright &y& Elsevier]

Abstract: In this study, 980nm high-power bottom-emitting vertical-cavity surface-emitting lasers (VCSELs) with large emission aperture are described. The devices have been fabricated by using oxidation confinement technology. Al2O3 film, instead of SiN x film, is used as the passivation layer to enhance heat dissipation. A distinguished device performance is achieved. The maximum continuous-wave (CW) output power of the large emission aperture devices with active diameters up to 500μm is as high as 1.95W at room temperature. [Copyright &y& Elsevier]

Abstract: Single devices and 2-D arrays of bottom-emitting vertical-cavity surface-emitting lasers operating in the 980nm wavelength regime, have been fabricated for high continuous-wave optical output power. Single devices with active diameters of 500μm show high output powers of 1.95 W at room temperature. Its threshold current is 510mA, and the maximum spatially averaged optical power density is 0.93kW/cm2. Arrays consisting of 16 elements of 200μm active diameters arranged in a square structure achieve output powers of 1.21 W corresponding to a power density of 1kW/cm2 spatially averaged over the effective array chip size. The device threshold current is 1.1A. [Copyright &y& Elsevier]

Photobiomodulation (PBM) using red or near-infrared (NIR) light has been used to stimulate the proliferation and differentiation of adipose-derived stem cells. The use of NIR wavelengths such as 810nm is reasonably well accepted to stimulate mitochondrial activity and ATP production via absorption of photons by cytochrome c oxidase. However, the mechanism of action of 980nm is less well understood. Here we study the effects of both wavelengths (810nm and 980nm) on adipose-derived stem cells in vitro. Both wavelengths showed a biphasic dose response, but 810nm had a peak dose response at 3J/cm 2 for stimulation of proliferation at 24h, while the peak dose for 980nm was 10-100 times lower at 0.03 or 0.3J/cm 2 . Moreover, 980nm (but not 810nm) increased cytosolic calcium while decreasing mitochondrial calcium. The effects of 980nm could be blocked by calcium channel blockers (capsazepine for TRPV1 and SKF96365 for TRPC channels), which had no effect on 810nm. To test the hypothesis that the chromophore for 980nm was intracellular water, which could possibly form a microscopic temperature gradient upon laser irradiation, we added cold medium (4°C) during the light exposure, or pre-incubated the cells at 42°C, both of which abrogated the effect of 980nm but not 810nm. We conclude that 980nm affects temperature-gated calcium ion channels, while 810nm largely affects mitochondrial cytochrome c oxidase., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Context: Identification of factors that enhance the proliferation of human dental mesenchymal stem cells (DMSCs) is vital to facilitate tissue regeneration. The role of low-level laser irradiation (LLLI) on proliferation of human DMSCs has not been well established., Objective: To assess the effect of LLLI on proliferation of human DMSCs when applied in-vitro., Data Sources: Electronic search of literature was conducted (2000-2016) on PubMed, Web of Science, and Scopus databases. Search terms included low-level light therapy, low-level laser irradiation, low-level light irradiation, LLLT, humans, adolescent, adult, cells, cultured, periodontal ligament, dental pulp, stem cells, dental pulp stem cells, mesenchymal stem cells, periodontal ligament stem cell, deciduous teeth, cell proliferation, adult stem cells, radiation, and proliferation., Results: The literature search identified 165 studies with 6 being eligible for inclusion; all used diode lasers; 5 studies used InGaAIP diode lasers; 4 used 660nm, and the other two applied 810nm or 980nm wavelength LLLI. The distance between the DMSCs and the laser spot ranged between 0.5mm to 2mm. The time intervals of cell proliferation analysis ranged from 0h to 7days after LLLI. After 660nm LLLI, an increase in the DMSC's proliferation was reported [DMSCs extracted from dental pulp of deciduous teeth (two irradiations, 3J/cm(2), 20mW was more effective than 40mW), adult teeth (two irradiations, 0.5 and 1.0J/cm(2), 30mW), and from adult periodontal ligament (two irradiations, 1.0J/cm(2) was more effective than 0.5J/cm(2), 30mW)]. Similarly, an increase in the proliferation of DMSCs extracted from dental pulp of adult teeth was reported after 810nm LLLI (7 irradiations in 7days, 0.1 and 0.2J/cm(2), 60mW) or 980nm LLLI (single irradiation, 3J/cm(2), 100mW). However, 660nm LLLI in one study did not increase the proliferation of DMSCs (single irradiation, energy densities of 0.05, 0.30, 7, and 42J/cm(2), 28mW)., Conclusion: There is limited evidence that in-vitro LLLI (660/810/980nm, with energy densities of 0.1-3J/cm(2)) increases the proliferation of DMSCs. Considering the limited evidence and their method heterogeneity it is difficult to reach a firm conclusion. Further research is necessary to identify the optimal characteristics of the LLLI setting (wave length, energy density, power output, frequency/duration of irradiations, distance between the cells and the laser spot/probe) to increase proliferation of DMSCs, and assess its impact on replicative senescence, as well as determine feasibility of the use in the clinical setting., (Copyright © 2016 Elsevier B.V. All rights reserved.)