Lasers at ∼900nm have been of vital importance in various fields, including material processing, underwater communications, and strong-field physics. Although Nd 3+ -doped materials employed for the laser, emission is strong competition with often more dominating ∼1060nm emission, which strongly limits output power applications. This paper proposes a direct coordination engineering approach, introduces halogen to nearest glass increasing bond covalency, leading stronger emissions than...

Eigenmode decomposition of the light field at output end optical fibers can provide fundamental insights into nature electromagnetic-wave propagation through fibers. Here we present a fast and complete modal technique for step-index The proposed employs digital holography to measure multimode fiber, utilizes orthonormal property basis modes calculate coefficients each mode. Optical experiments were carried out demonstrate technique, showing that this approach is fast, accurate cost-effective.

Large-size Al3+/Nd3+ co-doped silica glass with 5000 ppm Nd3+ and 50,000 Al3+ doping concentrations was prepared by the modified sol-gel method combined high-temperature melting molding technology. Electron probe micro-analyzer tests indicated that high homogeneity achieved this sample preparation method. The spectral properties of ions were evaluated. Nd3+-doped fiber (NDF) a core-to-clad ratio 20/125 μm drawn from preform as core. In laser oscillation experiment, maximum output power 14.6...

This paper reports, for the first time to our best knowledge, a nearly diffraction-limited output in Yb(3+)/Al(3+)/F(-) codoped double cladding silica fiber with 50 μm core diameter and 0.02 NA. The glass >6 mm was fabricated through solgel process combined high temperature sintering. Laser performances of this at different bend diameters were studied. mean M2<1.1 achieved 0.35 m. refractive index equal pure is suitable design, such as large-mode-area photonic crystal fiber.

Abstract High-power continuous-wave single-frequency Er-doped fiber amplifiers at 1560 nm by in-band and core pumping of a 1480 Raman laser are investigated in detail. Both co- counter-pumping configurations studied experimentally. Up to 59.1 W output 90% efficiency were obtained the fundamental mode linear polarization co-pumped case, while less power achieved counter-pumped setup for additional loss. The amplifier performs indistinguishably terms linewidth relative intensity noise...

Efficient NIR-to-NIR up-conversion emission (UCQY: 3.1%, 10 W cm⁻²) in β-NaYF₄:Yb³⁺,Tm³⁺ is obtained <italic>via</italic> ion-exchange for applications security.

Herein, we report the highly stable and efficient pure green up-conversion emission of β-NaGdF₄:Yb³⁺,Ho³⁺ rod-like submicro-crystals, synthesized <italic>via</italic> an ion-exchange method. This material shows great potential for fluorescence labeling applications.

We report a 30 cm long Nd3+/Yb3+ co-doped silica glass fiber amplifier with well-maintained broadband gain through simultaneous dual-laser pumping at 808 and 975 nm. By controlling the ratio of pump power (P975) nm (P808), emission band Yb3+/Nd3+ energy transfer efficiency Nd3+→Yb3+ can be well controlled; thus, tunable flat in range 1036-1080 are obtained. The theoretical calculation explains mechanism formation fiber.

Using a heavily erbium-doped aluminosilicate fiber prepared by the sol-gel method combined with high temperature sintering, dependence of spectrum around 1.55 nm band and single-mode laser properties were investigated, respectively. The absorption cross section increases 29.2% at ~1558 increasing from 20°C to 140°C, while emission slightly 4.3%. In addition, slope 1558 decreases 4.4% 10.8% 6.4% 18°C 440°C. Meanwhile, an experiment lasting 3 h proves that has excellent stability below

We report the demonstration of dual-wavelength laser output originating from excited Nd <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> ions and Yb in /Yb co-doped phosphate glass fiber under 970-nm diode pumping. Using a free-space coupling method, bands at 1028 1053 nm were observed 35-cm-long with corresponding lasing thresholds 4.3 31.5 W room temperature. Emission spectra different pump powers tested by optical spectrum analyzer....

The laser behavior of a centimeter-scale Er3+/Al3+ codoped silica fiber with core numerical aperture and diameter 0.15 8 μm, respectively, is reported. glass was prepared by the sol–gel method combined high-temperature sintering; it contained Er3+ ion concentration as high 1.32×1020 ions/cm3 an Al/Er mole ratio 10. doping homogeneity ions in confirmed electron probe microanalyzer element scanning, long Er3+: I13/24 emission lifetime 11.4 ms, low refractive index fluctuation (±1×10−4). signal...

The temperature dependence of energy transfer between Nd3+ and Yb3+ ions in phosphate glass was investigated with emission spectra, time-resolved spectroscopy, luminescence lifetimes. spectrograms vividly displayed processes both Nd3+→Yb3+ Yb3+→Nd3+ transfer. impact on rate has been studied by analyzing the cumulative rise times decay upon excitation at different temperatures. It found that are accelerated along increasing temperatures a certain range.

This work reports the generation of an optical-power tunable 1 μm dual-wavelength fiber laser in Nd3+/Yb3+ co-doped phosphate glass under 970 nm and 808 diode pumping. A bidirectional free-space pump setup was adopted. An can be easily realized by control power magnitude. Based on a series tests different conditions theoretical calculation Nd3+→Yb3+ energy transfer efficiency, mechanism found to stimulated emission modulation Nd3+ Yb3+ lasing. property is helpful enhance knowledge co-doping system.

Compared with Yb, Nd has potential in 1120 nm fiber lasers, the characteristics of larger emission cross section and four-level structure. In this work, Nd-doped (NDF) oscillator Nd-Raman (NRF) were built using single-mode 5/125 NDF to study lasing at nm, especially suppression amplified spontaneous 1060 nm. Limited by parasitic oscillation achieved 5 W output The NRF removed limitation due Raman shift from 1064 obtained an 7.7 a spectral peak-to-peak contrast 36 dB. This work provides...

A heterogeneous fiber with a Yb3+-doped fluorophosphate core and phosphate cladding was fabricated by the rod-in-tube stacking technique. The concentration of Yb3+ in glass can be up to 6×1020 ions/cm3. lasing threshold 900 mW, wavelength centered at 1043 nm. single-mode laser output slope efficiency 13.6% respect absorbed pump power obtained, for first time our knowledge. beam quality factor (M2) measured 1.25. Thus, is good alternative gain medium short-linear-cavity single-frequency laser.

The state-of-the-art smart city has been calling for an economic but efficient energy management over large-scale network, especially the electric power system. It is a critical issue to monitor, analyze and control loads of all users in In this paper, we employ popular computer vision techniques AI design non-intrusive load monitoring method management. First all, utilize both signal transforms (including wavelet transform discrete Fourier transform) Gramian Angular Field (GAF) methods map...

State-of-the-art smart cities have been calling for economic but efficient energy management over a large-scale network, especially the electric power system. It is critical issue to monitor, analyze, and control loads of all users in In this study, non-intrusive load monitoring method was designed using computer vision techniques popular artificial intelligence. First all, one-dimensional current signals are mapped onto two-dimensional color feature images signal transforms (including...

The interest in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mi mathvariant="normal">N</mml:mi> mathvariant="normal">d</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> <mml:mo>+</mml:mo> </mml:msup> <mml:mo>/</mml:mo> mathvariant="normal">Y</mml:mi> mathvariant="normal">b</mml:mi> </mml:math> co-doping was initially motivated by the discovery of <mml:mo stretchy="false">→</mml:mo> energy transfer 1964, which profoundly...