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Zaijin Fang - One of the best experts on this subject based on the ideXlab platform.

  • bismuth Doped Glass microsphere lasers
    Photonics Research, 2017
    Co-Authors: Zaijin Fang, Jibo Yu, Sile Nic Chormaic, Yuxuan Jiang, Shanyu Wang, Pengfei Wang
    Abstract:

    In this work, a hybrid structure consisting of a multicomponent germanate Glass microsphere containing bismuth as a gain medium is proposed and presented. The bismuth-Doped germanate Glass microspheres were fabricated from a Glass fiber tip with no precipitation of the bismuth metal. Coupling with a fiber taper, the bismuth-Doped microsphere single-mode laser was observed to lase at around 1305.8 nm using 808 nm excitation. The low threshold of absorbed pump power at 215 μW makes this microlaser appealing for various applications, including tunable lasers for a range of purposes in telecommunication, biomedical, and optical information processing.

  • Precisely controllable fabrication of Er3+-Doped Glass ceramic fibers: novel mid-infrared fiber laser materials
    Journal of Materials Chemistry C, 2017
    Co-Authors: Shiliang Kang, Zaijin Fang, Xiongjian Huang, Zhi Chen, Dandan Yang, Xiudi Xiao, Jianrong Qiu, Guoping Dong
    Abstract:

    We demonstrated remarkably enhanced 2.7 μm emission in Glass-ceramic (GC) fibers containing NaYF4:Er3+ nanocrystals with 980 nm excitation for the first time. The melt-in-tube technique is of scientific and technical significance for the fabrication of GC fibers in comparison to the conventional rod-in-tube technique. The obtained precursor fibers, in which the structure can be maintained well, exhibit no obvious element diffusion or crystallization during the fiber-drawing process. After a careful heat treatment, NaYF4 nanocrystals were controllably precipitated in the Glass fiber core. Owing to the incorporation of Er3+ ions into the low phonon energy NaYF4 nanocrystals, enhanced 2.7 μm emission was achieved from the Er3+-Doped GC fibers, which was almost undetectable in precursor fibers due to the high phonon energy of the borosilicate Glass fiber matrix. Moreover, the 2.7 μm emission lifetime was obtained due to the excellent emission properties of Er3+ in the GC fibers. The transmission loss values of precursor fibers and GC fibers at 1310 nm were measured to be 7.44 dB m−1 and 11.81 dB m−1, respectively. In addition, a theoretical simulation based on the rate equations and propagation equations was performed to evaluate the possibility of 2.7 μm laser output. The excellent optical properties endow the GC fibers with potential applications for mid-infrared fiber lasers.

  • ni 2 Doped Glass ceramic fiber fabricated by melt in tube method and successive heat treatment
    Optics Express, 2015
    Co-Authors: Zaijin Fang, Shupei Zheng, Wencai Peng, Hang Zhang, Shifeng Zhou, Guoping Dong, Danping Chen
    Abstract:

    Glass ceramic fibers containing Ni2+ Doped LiGa5O8 nanocrystals were fabricated by a melt-in-tube method and successive heat treatment. Fiber precursors were prepared by drawing at high temperature where fiber core Glass was melted while fiber clad Glass was softened. After heat treatment, LiGa5O8 nanocrystals were precipitated in the fiber core. Excited by 980 nm laser, efficient broadband near-infrared emission was observed in the Glass ceramic fiber compared to that of precursor fiber. The melt-in-tube method can realize controllable crystallization and is suitable for fabrication of novel Glass ceramic fibers. The Ni2+-Doped Glass ceramic fiber is promising for broadband optical amplification.

Jianrong Qiu - One of the best experts on this subject based on the ideXlab platform.

  • Precisely controllable fabrication of Er3+-Doped Glass ceramic fibers: novel mid-infrared fiber laser materials
    Journal of Materials Chemistry C, 2017
    Co-Authors: Shiliang Kang, Zaijin Fang, Xiongjian Huang, Zhi Chen, Dandan Yang, Xiudi Xiao, Jianrong Qiu, Guoping Dong
    Abstract:

    We demonstrated remarkably enhanced 2.7 μm emission in Glass-ceramic (GC) fibers containing NaYF4:Er3+ nanocrystals with 980 nm excitation for the first time. The melt-in-tube technique is of scientific and technical significance for the fabrication of GC fibers in comparison to the conventional rod-in-tube technique. The obtained precursor fibers, in which the structure can be maintained well, exhibit no obvious element diffusion or crystallization during the fiber-drawing process. After a careful heat treatment, NaYF4 nanocrystals were controllably precipitated in the Glass fiber core. Owing to the incorporation of Er3+ ions into the low phonon energy NaYF4 nanocrystals, enhanced 2.7 μm emission was achieved from the Er3+-Doped GC fibers, which was almost undetectable in precursor fibers due to the high phonon energy of the borosilicate Glass fiber matrix. Moreover, the 2.7 μm emission lifetime was obtained due to the excellent emission properties of Er3+ in the GC fibers. The transmission loss values of precursor fibers and GC fibers at 1310 nm were measured to be 7.44 dB m−1 and 11.81 dB m−1, respectively. In addition, a theoretical simulation based on the rate equations and propagation equations was performed to evaluate the possibility of 2.7 μm laser output. The excellent optical properties endow the GC fibers with potential applications for mid-infrared fiber lasers.

  • photoluminescence of eu3 tb3 and tm3 Doped transparent sio2 al2o3 lif gdf3 Glass ceramics
    Journal of Alloys and Compounds, 2009
    Co-Authors: G Lakshminarayana, Jianrong Qiu
    Abstract:

    Abstract In this paper, we present the photoluminescence properties of Eu 3+ , Tb 3+ and Tm 3+ -Doped oxyfluoride alumino-silicate Glasses and Glass ceramics. The X-ray diffraction (XRD) and differential thermal analysis (DTA) profiles of these Glasses have been carried out, to confirm their structure and thermal stability. Compared to Eu 3+ , Tb 3+ and Tm 3+ -Doped Glasses, their respective Glass ceramics have shown stronger emissions due to the presence of LiGdF 4 crystalline phase. For Eu 3+ -Doped Glass and Glass ceramics, five emission bands centered at 578 nm ( 5 D 0  →  7 F 0 ), 592 nm ( 5 D 0  →  7 F 1 ), 614 nm ( 5 D 0  →  7 F 2 ), 652 nm ( 5 D 0  →  7 F 3 ) and 698 nm ( 5 D 0  →  7 F 4 ) have been observed with 394 nm ( 5 D 0  →  7 L 6 ) excitation wavelength. Of them, 614 nm ( 5 D 0  →  7 F 2 ) has shown bright reddish-orange emission. With regard to the Tb 3+ -Doped Glass and Glass ceramic, four emission bands centered at 491 nm ( 5 D 4  →  7 F 6 ), 545 nm ( 5 D 4  →  7 F 5 ), 587 nm ( 5 D 4  →  7 F 4 ) and 622 nm ( 5 D 4  →  7 F 3 ) have been observed with an excitation at 377 nm ( 3 F 6  →  5 G 6 ) wavelength. Of them, 545 nm ( 5 D 4  →  7 F 5 ) has shown bright green emission. Emission bands of 1 G 4  →  3 F 4 (650 nm) and 3 F 3  →  3 H 6 (708 nm) transitions for the Tm 3+ :Glass and Glass ceramic, with an excitation at 3 H 6  →  1 G 4 (469 nm) have been observed. The stimulated emission cross-sections of all the emission bands of Eu 3+ , Tb 3+ and Tm 3+ :Glasses and Glass ceramics have been computed based on their measured full-width at half maximum (FWHM, Δ λ ) and lifetimes ( τ m ).

  • enhanced cooperative quantum cutting in tm3 yb3 coDoped Glass ceramics containing laf3 nanocrystals
    Optics Express, 2008
    Co-Authors: Bin Zhu, Jin Luo, Jingxin Chen, G Lakshminarayana, Jianrong Qiu
    Abstract:

    Tm(3+)-Yb(3+) coDoped transparent oxyfluoride Glass ceramics containing LaF(3) nanocrystals were obtained by thermal treatment on the as-made Glasses. The formation of LaF(3) nanocrystals and the incorporation of Tm(3+) and Yb(3+) into LaF(3) nanocrystal lattice were confirmed by X-ray diffraction and high resolution transmission electron microscopy. Infrared quantum cutting involving Yb(3+) 950-1100 nm ((2)F(5/2)--> (2)F(7/2)) emission was achieved upon the excitation of the (1)G(4) energy level of Tm(3+) at 468 nm. We measured the photoluminescence properties of these Glass ceramics. We also investigated the thermal treatment duration dependent quantum efficiency, and found that the quantum efficiency is 13% increased for the 0.5Tm(3+)-4Yb(3+) Doped Glass ceramic with a maximum value of 144%, and 16% increased for the 0.5Tm3+-8Yb3+ Doped Glass ceramic with a maximum value of 162%, respectively.

  • enhanced multiphoton absorption induced luminescence in transparent sm3 Doped ba2tisi2o8 Glass ceramics
    Journal of Physical Chemistry C, 2007
    Co-Authors: Bin Zhu, Shifeng Zhou, S K Zhang, Geng Lin, Jianrong Qiu
    Abstract:

    Fresnoite, Ba 2 TiSi 2 O 8 , is a ferroelectric crystal with a very large second-order optical nonlinearity. X-ray diffraction analysis and Raman spectra indicate that Ba 2 TiSi 2 O 8 crystals are precipitated in the Glass-ceramics after heat treatment at 750 °C for 2 h. Near-infrared to visible upconversion luminescence is observed in Sm 3+ -Doped Glass and Glass-ceramic samples under infrared femtosecond laser irradiation, and the Sm 3+ -Doped Glass-ceramic shows strongly enhanced mutiphoton absorption induced luminescence and improved saturate threshold compared with the as-prepared Glass. The mechanisms of the observed phenomena are discussed.

H H Horhold - One of the best experts on this subject based on the ideXlab platform.

  • light amplification and lasing in a stilbenoid compound Doped Glass clad polymer optical fiber
    IEEE Journal of Quantum Electronics, 2003
    Co-Authors: Takeyuki Kobayashi, Werner J Blau, H Tillmann, H H Horhold
    Abstract:

    We report on a large optical gain, over the wide spectral range, and lasing in a Glass-clad polymer optical fiber that uses a novel highly fluorescent stilbenoid compound. The compound 1,4-bis(4-diphenylamino-styryl)-benzene is designed for the blue region of the spectrum and has a high quantum yield of 0.85 in polystyrene and a relatively large Stokes shift of /spl sim/50 nm. A fiber Doped with 0.2-wt.% of the compound is photoexcited with a thin striped-shape area at 355 nm with nanosecond optical pulses, and the emission from one end is monitored as a function of the excitation length to deduce the net gain coefficient. The gain spectroscopy has revealed a broad optical gain exceeding 25 cm/sup -1/ and up to 36 cm/sup -1/ at 494 nm that covers a wide spectral range of about 70 nm when the fiber is transversely photoexcited at 12 mJ/cm/sup 2/ at room temperature. An analysis shows that the saturation effect expected for homogeneously broadened gain accounts for the amplified spontaneous emission output behavior at longer excitation lengths. Waveguide loss is measured to be 0.7 cm/sup -1/ at 494 nm. The large gain and low loss have been utilized to demonstrate blue laser emission at 489 nm from the fiber (which is only 1.4 cm in length) in a low finesse cavity defined by the Fresnel reflections at the fiber-air interfaces. The threshold for lasing is found to be 1.7 mJ/cm/sup 2/.

  • blue lasing from a stilbenoid compound Doped Glass clad polymer optical fibre
    Journal of Optics, 2002
    Co-Authors: Takeyuki Kobayashi, Werner J Blau, H Tillmann, H H Horhold
    Abstract:

    We report on blue lasing from a step index Glass–clad polymer optical fibre Doped with a novel fluorescent stilbenoid compound, 1,4-bis(4-diphenylamino-styryl)-benzene. The compound has a very high quantum yield of 0.85 in polystyrene and a relatively large Stokes shift of 50 nm. The Glass–clad fibre is fabricated by drawing a liquid solution of polystyrene containing the compound along into a Glass capillary. When the fibre only 1.4 cm in length is photopumped at 355 nm with nanosecond pulses, lasing at 489 nm is observed from a simple cavity defined by the Fresnel reflections at the fibre endfaces.

K V Yumashev - One of the best experts on this subject based on the ideXlab platform.

  • structural characteristics and spectral properties of novel transparent lithium aluminosilicate Glass ceramics containing er yb nbo4 nanocrystals
    Journal of Luminescence, 2015
    Co-Authors: O S Dymshits, A M Malyarevich, K V Yumashev, A. A. Zhilin, I P Alekseeva, Ya M Tsenter, Pavel Loiko, N A Skoptsov, Xavier Mateos, A V Baranov
    Abstract:

    Abstract Transparent lithium aluminosilicate Glass-ceramics based on nanosized crystals of β-quartz solid solutions and Er,Yb orthoniobates are prepared for the first time, to our knowledge. According to X-ray diffraction analysis, parent Er,Yb-coDoped Glass contains (Er,Yb)NbO 4 nanocrystals with the defected fluorite structure while the single Yb-Doped Glass is X-ray amorphous. The Er,Yb orthoniobates with the tetragonal structure crystallize under heat-treatments at 800–900 °C; and at 1000 °C the transformation to a monoclinic form begins. β-quartz solid solutions are the main crystalline phase of Glass-ceramics prepared in the temperature range of 800–1000 °C. These structural transformations are confirmed by Raman spectroscopy. The structure evolution is illustrated by the TEM study of the Yb-Doped Glass and Glass-ceramics. The spectral-luminescent properties of Glass-ceramics are directly linked to their structure; an appearance of the monoclinic phase has a crucial effect on these properties. Glass-ceramics with tetragonal (Er,Yb)NbO 4 nanophase are characterized by the high efficiency of Yb 3+ →Er 3+ energy transfer (85%), strong absorption in the vicinity of 0.98 μm and shorter lifetime of 4 I 13/2 state (as compared with the parent Glass), so they look promising for laser operation in the eye-safe region around 1.53 μm.

  • semiconductor Doped Glass saturable absorbers for near infrared solid state lasers
    Journal of Applied Physics, 2008
    Co-Authors: A M Malyarevich, K V Yumashev, A A Lipovskii
    Abstract:

    A survey of results on use of semiconductor-Doped Glass saturable absorbers for near-infrared passively mode-locked and Q-switched solid-state lasers is presented. Nanosized semiconductor particles (quantum dots) belong to quantum confined systems where motion of an electron and a hole is defined by the finite size of the nanoparticle. Dependence of the excitonic transition energy on the QDs size provides the possibility to tune the absorption of the Glasses embedded with such particles to wavelength of specific light source. IV-VI semiconductor QDs (PbS, PbSe) are of interest for IR application due to their narrow band gap and large exciton Bohr radii. These allow for exciton absorption band at the wavelength through 1–3μm. Nonlinear optical properties of PbS, PbSe, and CuxSe nanoparticles embedded in Glass matrices necessary for saturable absorber applications are analyzed. It is shown that these materials can be efficiently used for passive mode locking and Q switching of solid-state lasers based on Nd...

  • diode pumped nd yvo4 and nd kgd wo4 2 1 3 mu m lasers passively q switched with pbs Doped Glass
    Applied Physics B, 2003
    Co-Authors: V G Savitski, A M Malyarevich, K V Yumashev, B D Sinclair, A A Lipovskii
    Abstract:

    Diode-pumped Nd:YVO4 and Nd:KGW lasers passively Q-switched with PbS-quantum dot-Doped phosphate Glass were demonstrated. For the Nd:YVO4 laser, pulses 110 ns in duration with a 13% Q-switching efficiency were obtained. The absorption recovery time of the PbS-Doped Glass was measured to be 27 +/- 4 ps. Some recommendations for more efficient use of PbS-Doped Glasses for Q-switching of diode-pumped lasers are suggested on the basis of our analysis.

  • Glass Doped with pbs quantum dots as a saturable absorber for 1 mu m neodymium lasers
    Journal of The Optical Society of America B-optical Physics, 2002
    Co-Authors: A M Malyarevich, E Raaben, P.v. Prokoshin, N.n. Posnov, K V Yumashev, V G Savitski, A. A. Zhilin
    Abstract:

    Saturable-absorber mode locking and Q switching of neodymium-Doped lasers at 1.06 µm with a PbS-Doped Glass were demonstrated. Q-switched pulses of 0.3 µJ in energy and 15 ns in duration from a cw diode-pumped Nd3+:KGd(WO4)2 laser and ultrashort pulses of 18 µJ in energy and 70 ps in duration from a Nd3+:Y3Al5O12 laser were obtained. The saturation intensity of the PbS-Doped Glass (with an average semiconductor crystallite radius of 1.7 nm) was estimated to be 2.3 MW/cm2 at 1.06 µm. The bleaching relaxation time was measured to be 23 ps.

  • saturable absorber co 2 mgal 2 o 4 crystal for q switching of 1 34 µm nd 3 yalo 3 and 1 54 µm er 3 Glass lasers
    Applied Optics, 1999
    Co-Authors: K V Yumashev
    Abstract:

    Saturable-absorber Q switching of a neodymium-Doped YAlO3 laser at 1.34 µm and an erbium-Doped Glass laser at 1.54 µm with a Co2+:MgAl2O4 crystal was demonstrated. Q-switched 1.34-µm pulses of 19-mJ energy and 60-ns duration and Q-switched 1.54-µm pulses of 2.7-mJ energy and 75-ns width were obtained. The ground-state absorption cross sections of the Co2+:MgAl2O4 crystal were estimated to be (2.8 ± 0.4) × 10-19 and (3.5 ± 0.6) × 10-19 cm2 at 1.34 and 1.54 µm, respectively. The 4T1(4F) → 4A2 relaxation time of the Co2+ ion in the MgAl2O4 crystal was measured to be ∼350 ns.

A M Malyarevich - One of the best experts on this subject based on the ideXlab platform.

  • structural characteristics and spectral properties of novel transparent lithium aluminosilicate Glass ceramics containing er yb nbo4 nanocrystals
    Journal of Luminescence, 2015
    Co-Authors: O S Dymshits, A M Malyarevich, K V Yumashev, A. A. Zhilin, I P Alekseeva, Ya M Tsenter, Pavel Loiko, N A Skoptsov, Xavier Mateos, A V Baranov
    Abstract:

    Abstract Transparent lithium aluminosilicate Glass-ceramics based on nanosized crystals of β-quartz solid solutions and Er,Yb orthoniobates are prepared for the first time, to our knowledge. According to X-ray diffraction analysis, parent Er,Yb-coDoped Glass contains (Er,Yb)NbO 4 nanocrystals with the defected fluorite structure while the single Yb-Doped Glass is X-ray amorphous. The Er,Yb orthoniobates with the tetragonal structure crystallize under heat-treatments at 800–900 °C; and at 1000 °C the transformation to a monoclinic form begins. β-quartz solid solutions are the main crystalline phase of Glass-ceramics prepared in the temperature range of 800–1000 °C. These structural transformations are confirmed by Raman spectroscopy. The structure evolution is illustrated by the TEM study of the Yb-Doped Glass and Glass-ceramics. The spectral-luminescent properties of Glass-ceramics are directly linked to their structure; an appearance of the monoclinic phase has a crucial effect on these properties. Glass-ceramics with tetragonal (Er,Yb)NbO 4 nanophase are characterized by the high efficiency of Yb 3+ →Er 3+ energy transfer (85%), strong absorption in the vicinity of 0.98 μm and shorter lifetime of 4 I 13/2 state (as compared with the parent Glass), so they look promising for laser operation in the eye-safe region around 1.53 μm.

  • semiconductor Doped Glass saturable absorbers for near infrared solid state lasers
    Journal of Applied Physics, 2008
    Co-Authors: A M Malyarevich, K V Yumashev, A A Lipovskii
    Abstract:

    A survey of results on use of semiconductor-Doped Glass saturable absorbers for near-infrared passively mode-locked and Q-switched solid-state lasers is presented. Nanosized semiconductor particles (quantum dots) belong to quantum confined systems where motion of an electron and a hole is defined by the finite size of the nanoparticle. Dependence of the excitonic transition energy on the QDs size provides the possibility to tune the absorption of the Glasses embedded with such particles to wavelength of specific light source. IV-VI semiconductor QDs (PbS, PbSe) are of interest for IR application due to their narrow band gap and large exciton Bohr radii. These allow for exciton absorption band at the wavelength through 1–3μm. Nonlinear optical properties of PbS, PbSe, and CuxSe nanoparticles embedded in Glass matrices necessary for saturable absorber applications are analyzed. It is shown that these materials can be efficiently used for passive mode locking and Q switching of solid-state lasers based on Nd...

  • diode pumped nd yvo4 and nd kgd wo4 2 1 3 mu m lasers passively q switched with pbs Doped Glass
    Applied Physics B, 2003
    Co-Authors: V G Savitski, A M Malyarevich, K V Yumashev, B D Sinclair, A A Lipovskii
    Abstract:

    Diode-pumped Nd:YVO4 and Nd:KGW lasers passively Q-switched with PbS-quantum dot-Doped phosphate Glass were demonstrated. For the Nd:YVO4 laser, pulses 110 ns in duration with a 13% Q-switching efficiency were obtained. The absorption recovery time of the PbS-Doped Glass was measured to be 27 +/- 4 ps. Some recommendations for more efficient use of PbS-Doped Glasses for Q-switching of diode-pumped lasers are suggested on the basis of our analysis.

  • Glass Doped with pbs quantum dots as a saturable absorber for 1 mu m neodymium lasers
    Journal of The Optical Society of America B-optical Physics, 2002
    Co-Authors: A M Malyarevich, E Raaben, P.v. Prokoshin, N.n. Posnov, K V Yumashev, V G Savitski, A. A. Zhilin
    Abstract:

    Saturable-absorber mode locking and Q switching of neodymium-Doped lasers at 1.06 µm with a PbS-Doped Glass were demonstrated. Q-switched pulses of 0.3 µJ in energy and 15 ns in duration from a cw diode-pumped Nd3+:KGd(WO4)2 laser and ultrashort pulses of 18 µJ in energy and 70 ps in duration from a Nd3+:Y3Al5O12 laser were obtained. The saturation intensity of the PbS-Doped Glass (with an average semiconductor crystallite radius of 1.7 nm) was estimated to be 2.3 MW/cm2 at 1.06 µm. The bleaching relaxation time was measured to be 23 ps.