•Glass-cladding GeSe core fibers were fabricated by a molten core drawing method.•The cores were found to be highly crystalline with extremely low oxygen.•The GeSe core fibers show sensitive photo ...response under illuminated states.•It possesses improved thermoelectric performance than that of bulk GeSe.
Multimaterial fibers which integrate novel materials and/or structures into fiber configuration aim at developing multiple functionalities and high performance. Here, we demonstrate a kind of multimaterial fibers with crystalline GeSe core and K9 glass cladding by the molten core drawing method. The as-drawn fibers undergo a change in electrical conductivity when externally illuminated by an 808 nm HeNe laser. Furthermore, the Seebeck coefficient of the fibers is comparable with bulk GeSe, while the resistance is 3–4 magnitude lower than that. The results show that the GeSe core fibers have promising applications in optical switch and thermoelectric conversion field.
A new way to improve the 1.53μm emission in Er3＋/Yb3＋ co-doped multicomponent phosphate glass was demonstrated by introducing silver nanoparticles （NPs） in rare-earth doped glass. The existence of Ag ...NPs was confirmed by absorption spectra and transmission electron microscopy （TEM） measurements. The homogeneous distribution of silver NPs could be observed by the TEM images. UV-Vis-NIR absorption spectra revealed that the surface plasmon band was centered at about 420 nm. The photoluminescence spectra of glass samples were used to investigate the effect of silver NPs on the fluorescence properties of Er3＋. Efficient 1.53μm emis-sion was obtained in prepared samples when pumped at 980 nm laser diode （LD）. The 1.53μm emission intensity could be enhanced 87% by doping 2 mol.% AgCl due to the increased localized field effect in the vicinity of NPs and the possible energy transfer from silver NPs to Er3＋ions. Our present work may point out one way to enhance the gain coefficient of Er3＋/Yb3＋ co-doped glass fiber.
Elemental bismuth (Bi) exhibits a high magnetoresistance as a typical example of semimetal, which has significant application in information technologies. Silicate glass-clad Bi core fibers were ...fabricated by a molten core method and maintained core diameter of 100–150µm and overall diameter of 300–450µm. X-ray diffraction (XRD) and micro-Raman spectra showed the core to be highly crystalline with no observed secondary phases. Electro-probe micro-analyzer (EPMA) measurements confirmed a very well-defined core-clad interface. Demonstration of fibers with high magnetoresistance core materials and the potential integration with current state of the art technologies represents the first step in providing the building blocks for all-fiber sensors.
•Glass-clad bismuth core optical fibers were successfully synthesized.•The cores were found to be highly crystalline and phase-pure.•The bismuth core in fibers have a huge magnetoresistance effect.•The bismuth core fibers have great potential utility in all-fiber sensors.
Solution-processed organo-lead halide perovskites have emerged as promising optical gain media for tunable coherent light sources. The lasing performance is generally determined by the as-synthesized ...crystal quality. Noble metal nanostructures have been widely utilized to enhance optical responses due to their unique property of localized surface plasmon resonance. Herein, we report a simple method to enhance the near-infrared amplified spontaneous emission (ASE) performance of MAPbI
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polycrystalline films by solution-processing a PMMA spacer layer and an Au NR-doped PMMA top layer on perovskite thin films. As a result, the ASE threshold of the triple-layer perovskite film was significantly reduced by around 36% and the ASE intensity increased by 13.9-fold, compared to the pristine film. The underlying mechanism was attributed to the combined effects of surface passivation by PMMA and plasmon resonance enhancement of Au NRs. The passivation effect results in suppressing the nonradiative recombination and prolonging excited state decay, which have been investigated by transient absorption and pump-probe measurements. The plasmon effect is systematically studied through distance-dependent and spectra-dependent plasmon enhanced emission. The perovskite films with PMMA and Au NR coating showed great stability for 180 min under intense pulse laser continuous irradiation. The improved ASE performance still remained after leaving the film under the atmosphere for more than one month. We have successfully demonstrated a highly stable and sustained ASE output from MAPbI
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films under pulse laser excitation. This study provides a general approach for exploring plasmonic nanostructures in combination with polymers in the development and application of low-cost solution-processed semiconductor lasers.
Highly stable enhanced near-infrared amplified spontaneous emission in solution-processed perovskite films by employing polymer and gold nanorods.
SnO
suffers from fast capacity fading in lithium-ion batteries due to large volume expansion as well as unstable solid electrolyte interphase. Herein, the design and synthesis of phosphorus bridging ...SnO
and graphene through covalent bonding are demonstrated to achieve a robust structure. In this unique structure, the phosphorus is able to covalently "bridge" graphene and tin oxide nanocrystal through PC and SnOP bonding, respectively, and act as a buffer layer to keep the structure stable during charging-discharging. As a result, when applied as a lithium battery anode, SnO
@P@GO shows very stable performance and retains 95% of 2nd capacity onward after 700 cycles. Such unique structural design opens up new avenues for the rational design of other high-capacity materials for lithium battery, and as a proof-of-concept, creates new opportunities in the synthesis of advanced functional materials for high-performance energy storage devices.
W-5% (mass fraction) Re composite powder was fabricated by a new cladding method. W-5%Re nozzles used for solid rocket motor (SRM) were produced by shrouded plasma spray forming (PSF). The change ...regularity with the sintering time for the compact density, structure, micro-hardness, tensile strength and compression strength of the nozzel under 2300 degreesC vacuum sintering was studied. The study result indicates that the lamellae structure, and vertical columnar grains, micron-sized pores and rough interlamellar contacts with gaps of sub-micron sizes between lamellaes are found in PSF deposits. The relative density, micro-hardness, ultimate tensile strength (UTS) and compressive strength of PSF deposits are 87.5 %, 321.4 HV sub(0.025), 57.9 MPa and 390.2 MPa respectively. With the sintering time prolonged from 2 h to 6 h and 8 h, the relative density and mechanical properties of W-Re alloy parts increase with the initial lamellar structure transformed into granular structure.After vacuum sintering for 8 h,
Tm super(3+) doped lead silicate glasses with good thermal stability were prepared by the melt-quenching method. Based on the absorption and emission spectra, Judd-Ofelt intensity parameters, ...absorption and emission cross sections, gain spectra, and sigma sub(e) x FWHM were calculated and analyzed. These results suggest that Tm super(3+) doped lead silicate glasses are promising as mid-infrared laser materials. Tm super(3+) doped lead silicate glass single mode (SM) fibers with cladding diameter of 125 mum and core diameter of 8.5 mum were then fabricated by the rod-in-tube technique. The Tm super(3+) doping concentration reached as high as 4.545 x 10 super(20) ions/cm super(3). ~2.0 mum amplified spontaneous emission (ASE) was realized in a 3.5-cm-long as-drawn SM fiber when pumped by a homemade single mode 1560 nm fiber laser. The results indicate that these Tm super(3+) doped lead silicate glass single mode fibers are promising fiber material for 2.0 mum fiber laser applications.
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