Ce,Gd：YAG transparent ceramic was prepared by tape casting and solid state reaction method. Meanwhile, its crystal structure, chemical state and luminous properties were discussed. The prepared samples are identified...Ce,Gd：YAG transparent ceramic was prepared by tape casting and solid state reaction method. Meanwhile, its crystal structure, chemical state and luminous properties were discussed. The prepared samples are identified as pure garnet structure by the XRD results. The valence states of tetravalent and trivalent Ce ions were identified distinctly by X-ray photoelectron spectroscopy. A strong broad band yellow emission was found in photoluminescence（PL） spectra. The quantum yield reached 90.2% at room temperature. When collaborated with a 1.0 mm × 1.0 mm flip-chip, a luminous efficiency（LE） as high as 116.5 lm/W with a correlated color temperature（CCT） of 6627 K at a power dissipation of 1.13 W at 350 m A was demonstrated, indicating that Ce,Gd：YAG transparent ceramics had a promising potential for high power white light-emitting diodes.展开更多
Mid-infrared （mid-IR） （2-20 μm） photonics has numerous chemical and biologic ＂fingerprint＂ sensing applications due to characteristic vibrational transitions of molecules in the mid-IR spectral region. Unfortun...Mid-infrared （mid-IR） （2-20 μm） photonics has numerous chemical and biologic ＂fingerprint＂ sensing applications due to characteristic vibrational transitions of molecules in the mid-IR spectral region. Unfortunately, compared to visible light and telecommunication band wavelengths, photonic devices and applications have been difficult to develop at mid-IR wavelengths because of the intrinsic limitation of conventional materials. Breaking a new ground in the mid-IR science and technology calls for revolutionary materials. Graphene, a single atom layer of carbon arranged in a honey-comb lattice, has various promising optical and electrical properties because of its linear dispersion band structure and zero band gap features. In this review article, we discuss recent research develop- ments on mid-IR graphene photonics, in particular ultrafast lasers and photodetectors. Graphene-photonics-based biochemical applications, such as plasmonic sensing, photo- dynamic therapy, and florescence imaging are also reviewed.展开更多
The fluorescence evolution along Tm3+-doped Zr F4–Ba F2–La F3–Al F3–Na F(ZBLAN) optical fibers, as well as amplified spontaneous emission in the UV-IR region with emphasis on 350 nm, 365 nm, and 450 nm, is studied...The fluorescence evolution along Tm3+-doped Zr F4–Ba F2–La F3–Al F3–Na F(ZBLAN) optical fibers, as well as amplified spontaneous emission in the UV-IR region with emphasis on 350 nm, 365 nm, and 450 nm, is studied,estimating optimal fiber lengths for amplification within the region. The fibers were diode-pumped with single and double lines(687 and/or 645 nm). Double-line pumping presents a quite superior efficiency for producing UV-blue signals with the benefit of requiring very short fibers, around 20 cm, compared to single-line pumping requiring more than 50 cm. A virtual cycle in which the pumps enhance each other’s absorption is the key to these systems.展开更多
基金Supported by the Major Program for Research on LED of Chinese Academy of Science(KZCC-EW-106)the National Key Research and Development Program of China(2016YFB0701003)the Natural Science Foundation of Fujian Province(2015j01231)
文摘Ce,Gd：YAG transparent ceramic was prepared by tape casting and solid state reaction method. Meanwhile, its crystal structure, chemical state and luminous properties were discussed. The prepared samples are identified as pure garnet structure by the XRD results. The valence states of tetravalent and trivalent Ce ions were identified distinctly by X-ray photoelectron spectroscopy. A strong broad band yellow emission was found in photoluminescence（PL） spectra. The quantum yield reached 90.2% at room temperature. When collaborated with a 1.0 mm × 1.0 mm flip-chip, a luminous efficiency（LE） as high as 116.5 lm/W with a correlated color temperature（CCT） of 6627 K at a power dissipation of 1.13 W at 350 m A was demonstrated, indicating that Ce,Gd：YAG transparent ceramics had a promising potential for high power white light-emitting diodes.
文摘Mid-infrared （mid-IR） （2-20 μm） photonics has numerous chemical and biologic ＂fingerprint＂ sensing applications due to characteristic vibrational transitions of molecules in the mid-IR spectral region. Unfortunately, compared to visible light and telecommunication band wavelengths, photonic devices and applications have been difficult to develop at mid-IR wavelengths because of the intrinsic limitation of conventional materials. Breaking a new ground in the mid-IR science and technology calls for revolutionary materials. Graphene, a single atom layer of carbon arranged in a honey-comb lattice, has various promising optical and electrical properties because of its linear dispersion band structure and zero band gap features. In this review article, we discuss recent research develop- ments on mid-IR graphene photonics, in particular ultrafast lasers and photodetectors. Graphene-photonics-based biochemical applications, such as plasmonic sensing, photo- dynamic therapy, and florescence imaging are also reviewed.
基金supported by the Mexican National Council of Science and Technology,CONACYT,under grant reference CB-2011-01/166740 and scholarship No.377309
文摘The fluorescence evolution along Tm3+-doped Zr F4–Ba F2–La F3–Al F3–Na F(ZBLAN) optical fibers, as well as amplified spontaneous emission in the UV-IR region with emphasis on 350 nm, 365 nm, and 450 nm, is studied,estimating optimal fiber lengths for amplification within the region. The fibers were diode-pumped with single and double lines(687 and/or 645 nm). Double-line pumping presents a quite superior efficiency for producing UV-blue signals with the benefit of requiring very short fibers, around 20 cm, compared to single-line pumping requiring more than 50 cm. A virtual cycle in which the pumps enhance each other’s absorption is the key to these systems.
