Photodarkening effect

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August undefined, 2024

Webphotodarkening effect, which manifests as a time dependent increase of loss in the doped core, is one of the main threats to the efﬁciency of the Yb-doped gain media leading to degradation of the laser performance. This thesis focused on developing accurate methods to characterize photodarkening and the WebA photobleaching effect is reported which reduces the broadband losses induced by the single-pulse writing of fiber Bragg gratings (FBGs). A primary application of the optical FBG reflector is as arrays of wavelength-encoded sensing elements for detecting mechanical strain. Instrumentation is being developed to interrogate >100 point sensors along a …

Effective suppression of photodarkening effect in high

WebDec 17, 2024 · The sensitivity of this effect to various experimental considerations is examined, including atmosphere, photon energy, photon dose, and also the role of perovskite composition and morphology; under certain conditions there can even be photodarkening effects. ... under certain conditions there can even be photodarkening effects. … WebWe examine the effect of photodarkening-induced pump light absorption on Yb-doped fiber thermal loading. In these experiments, the fiber is cladding pumped at 915nm, air cooled by natural convection, and monitored with a midinfrared thermal camera. The fiber temperature is found to correlate with progressive photodarkening. The maximum observed fiber … dichotomy artinya

Elimination of the Photodarkening Effect in an Yb-Doped Fiber

WebNov 5, 2024 · In this paper, we summarize the research on photodarkening in optical fibers. The causes of photodarkening in fiber, the influence of photodarkening on fiber laser, the … WebDec 10, 2013 · At this laser lever, we did not observe the photodarkening in our silica fiber. But codoping moderate P 2 O 5 with Al 2 O 3 in Yb 3+-doped silica fiber is necessary to greatly suppress photodarkening effect when the fiber is operating continuously at high-power. Further work to reduce optical loss and improve mode quality of output laser is ... WebDec 24, 2024 · To resolve the conflict between large mode field and beam quality, the structural design of the fiber and rare earth ion doping can be employed to suppress the photodarkening effect of the fiber (Jauregui et al., 2015; Petit et al., 2016). One of the important strategies adopted to increase the mode instability threshold is the preparation … dichotomy approach

Photodarkening effect in glassy As2S3 and As2O3

Photodarkening of ytterbium-doped large-mode-area photonic …

WebOct 21, 1983 · We studied the photodarkening effect in films of Ge 10 As 40 Se 25 S 25, Ge 25 Se 75 and Ge 22.5 As 10 Se 67.5. The transmissivities of the films were measured as a function of the exposure time and the contrast indices γ were obtained. These results were compared with values calculated from the rate equations, and the photodarkening … WebPhotodarkening effect of an ytterbium fibre under different pump wavelength. 2.3 Time behavior of photodarkening Photodarkening is an effect that occurs strongly at the beginning and then decreases to reach a stable value. dichotomy antonym meaningWebFeb 22, 2024 · However, in the late 1990s, photodarkening effect, i.e., the creation of color centers induced by light, was … Expand. 10. PDF. View 1 excerpt, references background; Save. Alert. Charge-transfer state excitation as the main mechanism of the photodarkening process in ytterbium-doped aluminosilicate fibres. citizen insurance company rating

"WebWe found co-doping of group-2 element effectively suppresses photo-darkening effect in Yb-doped silica fiber. Laser oscillation in Mg/Yb co-doped silica fiber of 37-mm was also demonstrated at power of 140.4-mW and slope efficiency of 41.5%. " - Photodarkening effect

Photodarkening effect

WebOct 1, 2003 · The main goal of this study is to investigate whether the photodarkening effect in glassy As 2 S 3 and As 2 O 3 is associated with changes in the asymmetry of the … WebThe radical elimination of photodarkening effect by H2-loading was demonstrated, and the output power was stable during long term operation in high power fiber amplifiers, without …

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WebThis study reports the radical elimination of the photodarkening (PD)-effect in Yb-doped fiber through deuterium loading. With deuterium pre-loading, no PD-induced excess loss … WebOct 15, 2012 · For some applications, however, the major bottleneck is the limit in the Yb doping level due to photodarkening (PD). 1 This effect causes propagation losses when the active fiber is pumped, and it has also been reported for fibers doped with other rare-earth elements, such as thulium. 2 The origin of PD is still unclear, but there is evidence ...

WebWe investigate the temporal evolution of photodarkening effect in ytterbium-doped large-mode-area photonic crystal fiber and discuss its mechanism. The results show the great influence of photodarkening on lasing properties. WebDec 1, 2024 · It was found that the sample fabricated using the powder derived with (NH 4) 2 SO 4 as a dispersant still exhibited photodarkening effect, as shown in Fig. 8. After irradiation by the 940 nm laser diode, a cross-like dark area became observable on the ceramic slab, while no photodarkening was observed on the sample fabricated using PAA …

WebThe sol-gel derived samples with 80 wt % SiO 2 do not exhibit appreciable photodarkening while the melt-quenched glasses with 56 wt % SiO 2 exhibit strong photodarkening … WebMar 1, 2024 · Simultaneous photodarkening and photobleaching effects induced by 976 and 405 nm radiations, respectively, were investigated in a 1070 nm laser and compared with …

WebWe study the influence of laser exposure on transient absorption in a commercial Schott color glass filter doped by CdSxSe1−x microcrystals. With laser exposure the magnitude of the transient absorption at wavelengths above the band gap (negative, with the fast decay rate ≥1011 s−1), decreases, whereas that at wavelengths below the band gap (positive, …

WebSisyphus effect; Skin whitening; Skyguard (airport defense system) Slapper detonator; Slope efficiency; Smith–Purcell effect; Smoke detector; Smoke screen; Sniper; Soft-tissue laser surgery; Soft laser desorption; Solar-pumped laser; Solar sail; Solid-state laser; Solid-state dye laser; Soviet laser pistol; Space-based solar power; Space debris citizen insurance company floridaWebIn the second part of the thesis, the photodarkening effect of Tm³⁺-doped NaYF₄ nanocrystals is studied. We have found that photodarkening behavior is observed in Tm³⁺-doped nanocrystals that exhibit the photon avalanche effect. Power-dependent luminescence of a single 8% Tm3+-doped nanocrystal reveals that photodarkened … dichotomy architectureWebThis paper examines the effects of gamma radiation on erbium-, ytterbium-, and Yb/Er co-doped optical fibers by exposing a suite of such fibers to radiation from a Co-60 source over long periods of time while monitoring the temporal and spectral decrease in transmittance of a reference signal. dichotomy a reeceWebDec 18, 2024 · Additionally, the nonlinear effects (NLEs) [2,7] and photodarkening (PD) effects [8][9] [10] should be considered in the amplifiers. To suppress NLEs, the doping … dichotomy between agency and constraintWebOct 25, 2024 · To darken part of an image in Photoshop, first, create an Exposure Adjustment Layer and place it at the top of the Layers Panel. Next, access the Brush Tool … dichotomy art historyPhotodarkening is an optical effect observed in the interaction of laser radiation with amorphous media (glasses) in optical fibers. Until now, such creation of color centers was reported only in glass fibers. Photodarkening limits the density of excitations in fiber lasers and amplifiers. The experimental results … See more One could expect the term photodarkening to refer to any process when any object becomes non-transparent (dark) due to illumination with light. Formally, the darkening of the photo-emulsion also could be considered … See more The phenomenon, similar to photodarkening in fibers, was recently observed in chunks of Yb-doped ceramics and crystals. At the high concentration of excitations, the See more The inverse of the timescale at which photodarkening occurs can be interpreted as photodarkening rate. See more Usually, photodarkening is attributed to creation of color centers due to resonant interaction of electromagnetic field with an active medium. See more dichotomy as a verbWebAcademia.edu is a platform for academics to share research papers. citizen insurance company claims