Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences
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Enhanced 2.86 mu m emission of Ho3+,Pr3+ - codoped LaF3 single crystal
No full textNational Natural Science Foundation of China [51472257, 51502321]; National Key Research and Development Program of China [2016YFB0701002, 2016YFB1102302, 2016YFB0402105]; Strategic Priority Research Program [XDB16]; Major Project of Shanghai Science and Technology Research Foundation [16JC1420600]A novel Ho3+, Pr3+-codoped LaF3 mid-IR laser crystal was successfully grown and analyzed. Enhanced emission at similar to 2.86 mu m was observed for the first time. The effect of Pr3+ co-doping on the similar to 2.86 mu m photoluminescence of Ho3+ was investigated. Compared with Ho3+ singly-doped LaF3 crystal, the Ho3+, Pr3+-codoped LaF3 crystal possessed stronger emission intensities at similar to 2.86 mu m. It was also found that the energy transfer efficiency of Ho3+: I-5(7) -> Pr3+: F-3(2) (71%) is much greater than that of Ho3+: I-5(6) -> Pr3+: F-3(4) (28%), which almost restrained the self-termination problem in this Ho3+:Pr3+:LaF3 crystal. All the results indicated that Ho:Pr:LaF3 crystal is an attractive laser medium for similar to 2.86 mu m laser applications. (C) 2017 Optical Society of America
Low-temperature-flux syntheses of ultraviolet-transparent borophosphates Na4MB2P3O13 (M = Rb, Cs) exhibiting a second-harmonic generation response
No full textNational Natural Science Foundation of China [51432006, 50925207, 51172100]; Ministry of Science and Technology of China [2011DFG52970]; Ministry of Education of China for the Changjiang Innovation Research Team [IRT13R24]; Ministry of Education; State Administration of Foreign Experts Affairs for 111 Project [B13025]; Australian Research CouncilThe first non-centrosymmetric mixed-alkali-metal borophosphates, Na4MB2P3O13 (M = Rb 1, Cs 2), were obtained using a low-temperature flux method. Single-crystal X-ray diffraction studies of 1 and 2 reveal that the two compounds are isostructural, both crystallizing in the orthorhombic space group Pna2(1); their structures consist of novel 1D borophosphate chains constructed from B2P3O14 fundamental building units, assembled into a 3D framework by alkali metal cations. Second-harmonic generation (SHG) measurements show that 1 and 2 are type-I phase-matchable, with SHG responses ca. 0.35 and 0.42 times that of KH2PO4, respectively. The cut-off edges of 1 and 2 are ca. 276 and 267 nm, respectively, which suggests that they are potential ultraviolet nonlinear optical materials. Density functional theory calculations were employed to shed light on the band structure and density of states as well as the electron density distribution
Measuring optical constants of ultrathin layers using surface-plasmon-resonance-based imaging ellipsometry
No full textNational Natural Science Foundation of China (NSFC) [61405219]; National Key Research and Development Project of China [2016YFE0104300]; Italian-Chinese Project of Great Relevance [PGR00799]A setup for surface-plasmon-resonance-(SPR) based imaging ellipsometry was developed, which gains from the sensitivities of both SPR and ellipsometry to ultrathin film parameters. It is based on Otto's configuration for prism -sample coupling and a wide-beam imaging ellipsometry. A set of ultrathin gold and silver films was measured to determine their optical constants and thicknesses. Coupling the sample using a prism with a convex surface enables us to capture images of generated SPR elliptical fringes, which correspond to different SPR amplitude values at different air gap thicknesses. Analysis of the images acquired at different polarizer and analyzer angles provides the ellipsometric functions. and. versus thickness of air gap and hence the extraction of the optical constants of ultrathin metal films. The measured film thickness is in agreement with the results of x-ray reflectivity measurements
Novel gallium-doped amorphous calcium phosphate nanoparticles: Preparation, application and structure study
No full textNational Natural Science Foundation of China [NSFC 61475174]; Chinese Academy of SciencesNovel gallium-doped amorphous calcium phosphate (ACP) nanoparticles with different (Ga + Ca)/P molar ratio (1.8-3.0) were synthesized using sol-gel method. The antibacterial effects of the gallium-doped ACP samples were tested using disk diffusion assays, against Pseudomonas aeruginosa. The results showed that the gallium doped ACP samples have obvious effect of inhibiting the growth of Pseudomonas aeruginosa and could have a long term antibacterial properties. The local structures of these amorphous calcium phosphate nanoparticles were studied by P-31, Ga-71 single pulse, double-resonance and P-31 homonuclear dipolar recoupling solid state NMR techniques. The solid state NMR studies indicate that gallium-doped ACP nanoparticles are consisted of Gax(OH)yOz and calcium phosphate clusters. Gallium-doped ACP nanoparticles could be promising complex materials with the properties of antibacterial and biological mineralization
Passively Q-Switched Tm:CaYAlO4 Laser Using a MoS2 Saturable Absorber
No full textNational Natural Science Foundation of China [61575164]; Specialized Research Fund for the Doctoral Program of Higher Education [20130121120043]; Natural Science Foundation of Fujian Province of China [2014J01251]; China High-End Foreign Expert ProgramWe report here for the first time on the diode-pumped continuous-wave laser operation of an a-cut Tm: CaYAlO4 (CYAO) crystal in a two-mirror laser configuration at about 1850 nm, which is the shortest laser wavelength ever achieved with this material, with a maximum output power of 0.88 W. Using a MoS2 saturable absorber deposited directly onto the surface of the output coupler, the Tm: CYAO laser is then operated in the Q-switched mode with a maximum output power of 0.49 W and the narrowest pulse width of 0.48 mu s
Preparation and luminescence of Ce: YAG transparent glass ceramics by liquid-phase sintering
No full textNational Nature Science Foundation of China [61378069, 61378069, 61405221]; Youth Innovation Promotion Association of the Chinese Academy of SciencesA Ce: YAG transparent glass ceramic was prepared by liquid-phase sintering of a mixture of YAG-Al2O3-PbO-PbF2-B2O3 precursor glass with Ce: YAG nanocrystals. The microstructure, luminescence spectra and lifetime behaviors of the sample was investigated. The size of the YAG crystals inside the GC reached similar to 20 mu m. The average in-line transmittance (2-mm thick) of the GC was more than 56% in the visible region. The GC exhibited a broad yellow emission band, long lifetime (tau = 1.69 ms), good transparency, and low sintering temperature, implying that the composite is a promising candidate for high-power white light emitting diodes (WLEDs). (C) 2017 Elsevier B. V. All rights reserved
Preparation and Optical Properties of Infrared Transparent 3Y-TZP Ceramics
No full textNational Youth Natural Science Foundation of China [51302284, 6140031038]In the present study, a tough tetragonal zirconia polycrystalline (Y-TZP) material was developed for use in high-speed infrared windows and domes. The influence of the preparation procedure and the microstructure on the material's optical properties was evaluated by SEM and FT-IR spectroscopy. It was revealed that a high transmittance up to 77% in the three-to five-micrometer IR region could be obtained when the sample was pre-sintered at 1225 degrees C and subjected to hot isostatic pressing (HIP) at 1275 degrees C for two hours. The infrared transmittance and emittance at elevated temperature were also examined. The in-line transmittance remained stable as the temperature increased to 427 degrees C, with degradation being observed only near the infrared cutoff edge. Additionally, the emittance property of 3Y-TZP ceramic at high temperature was found to be superior to those of sapphire and spinel. Overall, the results indicate that Y-TZP ceramic is a potential candidate for high-speed infrared windows and domes
Structural Studies of Fluoroborate Laser Glasses by Solid State NMR and EPR Spectroscopies
No full textNational Natural Science Foundation of China [NSFC 61475174]; 100 Talents Program of Chinese Academy of Sciences; FAPESP [2013/07793-6, 2013/23490-3, 2015/04063-2]; CNPq [477053/2012-2, 479672/2012-1]The structure of glasses in the systems (100 - x)B2O3-xPbF(2) (x = 30, 40, and 50) and 50B(2)O(3)-(50 - x)PbO-xPbF(2) (x = 5, 10, 15, 20, 25, 30, 35, 40, and 45) has been studied by solid state NMR and EPR spectroscopies.-On the basis Of B-11 and F-19 high resolution solid state NMR as well as on B-11/F-19 double resonance results, we develop a quantitative structural description on the atomic scale. F-19 NMR results indicate a systematic dependence of the fluoride speciation on PbF2 content: At low x-values, F- ions are predominantly found on BO3/2F- units, whereas, at higher x-values, fluoride tends to be sequestrated into amorphous domains rich in PbF2. In addition, both pulsed EPR studies of Yb3+ doped glasses and photophysical studies of Eu3+ doped samples indicate a mixed fluoride/borate coordination of the rare-earth ions, and the absence of nanophase segregation effects
Tb3Al2.5 Ga2.5O12 transparent ceramic for magneto-optical application
No full textNatural Science Foundation of China [61475172, 51172254, 51202269]The optical quality and microstructure of the Tb3Al2.5 Ga2.5O12 transparent ceramic were investigated and compared with those of terbium gallium garnet (Tb3Ga5O12 TGG) and terbium aluminum garnet (Tb3Al5O12 TAG). The transmission of the Tb3Al2.5 Ga2.5O12 ceramic was as high as 80% in the visible and near-infrared (IR) regions, which was close to the theoretical value. The Verdet constant of the Tb3Al2.5 Ga2.5O12 ceramic measured at 632.8 nm and room temperature was similar to 150.6 rad/Tm, which was 12% larger than that of the TGG single crystal and 13% smaller than that of the TAG single crystal, and the Tb3Al2.5 Ga2.5O12 ceramic showed the highest transparency among these three samples
Yb3+-doped silica glass rod with high optical quality and low optical attenuation prepared by modified sol-gel technology for large mode area fiber
No full textNational Natural Science Foundation of China [61505232, 61405215]We report on a modified sol-gel method combined with an innovative high-temperature melting technology for the preparation of Yb3+-doped silica glass rods (circle divide 3-18 mm) with high optical quality and low background loss. We prepared Al-Yb, Al-P-Yb, Al-FYb, and Al-P-F-Yb doped silica glass rods for large mode area fibers (LMA) with a high laser power and low core numerical aperture (0.02). We were able to successfully solve the doping homogeneity problem caused by the volatility of P and F. More importantly, we developed a purification technology and successfully reduced the optical attenuation to 0.05 dB/m. An Al-Yb co-doped silica photonic crystal fiber (PCF) with a core diameter of 100 mu m was fabricated for laser behaviour characterization. In the continuous wavelength laser measurement, a laser output slope efficiency of 83.3% was obtained from the fabricated PCF. To our knowledge, this is the highest slope efficiency derived from a Yb3+-doped silica PCF prepared by a non-CVD method. In the pulse amplification laser experiment, an average amplified power of 310 W with a peak power of 1.5 MW and a pulse duration of 21 ps were achieved