Wangwang Liu
South China University of Technology
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Featured researches published by Wangwang Liu.
Optics Express | 2015
Guowu Tang; Qi Qian; Xin Wen; Xiaodong Chen; Wangwang Liu; Min Sun; Zhongmin Yang
Phosphate glass-clad optical fibers comprising amorphous Se(0.8)Te(0.2) semiconductor core were fabricated by a reactive molten core approach. The Se(0.8)Te(0.2) crystals were precipitated in core region by a postdrawing annealing process, which were confirmed by X-ray diffraction, micro-Raman spectra, electron probe X-ray micro-analyzer, and transmission electron microscope measurement results. A two-cm-long crystalline Se(0.8)Te(0.2) semiconductor core optical fiber, electrically contacted to external circuitry through the fiber end facets, exhibits a two-orders-of-magnitude change in conductivity between dark and illuminated states. The great discrepancy in light and dark conductivity suggests that such crystalline Se(0.8)Te(0.2) semiconductor core optical fibers have promising applications in optical switch and photoconductivity of optical fiber array.
Optical Materials Express | 2016
Guowu Tang; Tingting Zhu; Wangwang Liu; Wei Lin; Tian Qiao; Min Sun; Dongdan Chen; Qi Qian; Zhongmin Yang
Tm3+ 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 σe × FWHM were calculated and analyzed. These results suggest that Tm3+ doped lead silicate glasses are promising as mid-infrared laser materials. Tm3+ doped lead silicate glass single mode (SM) fibers with cladding diameter of 125 μm and core diameter of 8.5 μm were then fabricated by the rod-in-tube technique. The Tm3+ doping concentration reached as high as 4.545 × 1020 ions/cm3. ~2.0 μm 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 Tm3+ doped lead silicate glass single mode fibers are promising fiber material for 2.0 μm fiber laser applications.
Journal of Rare Earths | 2016
Xiujie Shan; Guowu Tang; Xiaodong Chen; Shuai Peng; Wangwang Liu; Qi Qian; Dongdan Chen; Zhongmin Yang
Abstract A new way to improve the 1.53 μm emission in Er 3+ /Yb 3+ 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 Er 3+ . Efficient 1.53 μm emission was obtained in prepared samples when pumped at 980 nm laser diode (LD). The 1.53 μm 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 Er 3+ ions. Our present work may point out one way to enhance the gain coefficient of Er 3+ /Yb 3+ co-doped glass fiber.
APL Materials | 2018
Min Sun; Qi Qian; Guowu Tang; Wangwang Liu; Guoquan Qian; Zhenguo Shi; Kaimin Huang; Dongdan Chen; Shanhui Xu; Zhongmin Yang
Bi2Te3-based materials have been reported to be one of the best room-temperature thermoelectric materials, and it is a challenge to substantially improve their thermoelectric properties. Here novel Bi2Te3 core fibers with borosilicate glass cladding were fabricated utilizing a modified molten core drawing method. The Bi2Te3 core of the fiber was found to consist of hexagonal polycrystalline nanosheets, and polycrystalline nanosheets had a preferential orientation; in other words, the hexagonal Bi2Te3 lamellar cleavage more tended to be parallel to the symmetry axis of the fibers. Compared with a homemade 3-mm-diameter Bi2Te3 rod, the polycrystalline nanosheets’ preferential orientation in the 89-μm-diameter Bi2Te3 core increased its electrical conductivity, but deduced its Seebeck coefficient. The Bi2Te3 core exhibits an ultrahigh ZT of 0.73 at 300 K, which is 232% higher than that of the Bi2Te3 rod. The demonstration of fibers with oriented nano-polycrystalline core and the integration with an efficient fabrication technique will pave the way for the fabrication of high-performance thermoelectric fibers.Bi2Te3-based materials have been reported to be one of the best room-temperature thermoelectric materials, and it is a challenge to substantially improve their thermoelectric properties. Here novel Bi2Te3 core fibers with borosilicate glass cladding were fabricated utilizing a modified molten core drawing method. The Bi2Te3 core of the fiber was found to consist of hexagonal polycrystalline nanosheets, and polycrystalline nanosheets had a preferential orientation; in other words, the hexagonal Bi2Te3 lamellar cleavage more tended to be parallel to the symmetry axis of the fibers. Compared with a homemade 3-mm-diameter Bi2Te3 rod, the polycrystalline nanosheets’ preferential orientation in the 89-μm-diameter Bi2Te3 core increased its electrical conductivity, but deduced its Seebeck coefficient. The Bi2Te3 core exhibits an ultrahigh ZT of 0.73 at 300 K, which is 232% higher than that of the Bi2Te3 rod. The demonstration of fibers with oriented nano-polycrystalline core and the integration with an efficient ...
Chinese Physics B | 2017
Shuai Peng; Guowu Tang; Min Sun; Wangwang Liu; Xiujie Shan; Qi Qian; Dongdan Chen; Qinyuan Zhang; Zhongmin Yang
A method of fabricating selenium (Se) microwire is demonstrated. A multimaterial fiber with amorphous selenium (a-Se) core and multicomponent phosphate glass cladding is drawn by using a conventional optical fiber drawing technique. Then the a-Se core of the fiber is crystallized by a post thermal process at 150 °C. After the multicomponent phosphate glass cladding is stripped from the multimaterial fiber by marinating the fiber in HF acid solution, a crystalline selenium (c-Se) microwire with high uniformity and smooth surface is obtained. Based on microstructure measurements, the c-Se microwire is identified to consist of most hexagonal state particles and very few trigonal state whiskers. The good photoconduction property of c-Se microwire with high quality and longer continuous length makes it possible to apply to functional devices and arrays.
Journal of Alloys and Compounds | 2016
Guowu Tang; Xin Wen; Qi Qian; Tingting Zhu; Wangwang Liu; Min Sun; Xiaodong Chen; Zhongmin Yang
Journal of Alloys and Compounds | 2017
Guowu Tang; Wangwang Liu; Qi Qian; Guoquan Qian; Min Sun; Li Yang; Kaimin Huang; Dongdan Chen; Zhongmin Yang
Journal of Non-crystalline Solids | 2016
Guowu Tang; Zaijin Fang; Qi Qian; Guoquan Qian; Wangwang Liu; Zhenguo Shi; Xiujie Shan; Dongdan Chen; Zhongmin Yang
Materials Letters | 2018
Min Sun; Guowu Tang; Guoquan Qian; Wangwang Liu; Zhenguo Shi; Dongdan Chen; Qi Qian; Zhongmin Yang
Journal of Alloys and Compounds | 2017
Min Sun; Guowu Tang; Wangwang Liu; Guoquan Qian; Kaimin Huang; Dongdan Chen; Qi Qian; Zhongmin Yang