Photodarkening effect
WebThe photodarkening effect normally appears to be permanent, although it has been demonstrated that it can be reversed by heating the fiber [18] or by irradiation with ultraviolet light [19]. Further studies will hopefully reveal … 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 …
Photodarkening effect
Did you know?
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%. 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 of the Yb-doped fiber was observed under 915-nm pumping conditions. Moreover, the existing loss induced by the PD effect was also eliminated via deuterium loading, and the excess …
WebFirst, the radiation-induced photodarkening in erbium/ytterbium co-doped optical fibre (EYDF) and the thermal effect in these irradiated EYDFs have been studied, which evidently display a reversible thermal effect. ... When the EYDF is exposed to Co 60 γ-radiation, a significant photodarkening effect can be observed due to the RIA . By ... WebIn 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 …
WebJan 1, 2015 · ChG exhibits a photodarkening effect in which a red shift in the absorption edge occurs when visible light (of which the energy is larger than the bandgap of ChG) is used for illumination [18].Thus, to induce the maximal photodarkening effect of ChG, a high-power green laser (532 nm) is typically used.We obtained the transmission spectra (Fig. 3 … WebThis 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.
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 … trust based philanthropy modelWebNote that there are also various photodarkening effects in optical materials, e.g. some rare-earth-doped fibers, which may be reversible or irreversible. Operation Principle. Photochromic glasses are often made by embedding silver chloride (AgCl) or another silver halide in microcrystalline form into some glass. philipps and stubbsWebWe presented an experimental comparison of the core-composition difference on the suppression of the photodarkening and transverse mode instability effects. Two core-composition fibers, entailing Yb/Al/Ce and Yb/Al/P co-doped fibers, were fabricated by MCVD process combined with solution doping technique. The parameters of two fibers were … trust based relational intervention pdfWebphotodarkening 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 trust based relational intervention bookWebFeb 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. philipps angeboteWebThe 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 … philipp sarasin foucaultWebDec 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 ... philipps-apotheke marburg