| Nowdays high-power laser have been extensively utilized in many scientific and technological fields, such as industry, military and scientific, due to their high efficiency, high beam quality and high power capability. Traditionally YAG crystal or ceramics doped with rare-earth (Re) ions have been identified as excellent materials for high-power lasers, since they possess high conductivity, excellent optical and laser properties. In recent years, high-temperature Re sesquioxides such as Lu2O3, Y2O3and Sc2O3have been suggested to be potential materials for high-power lasers, because those materials possess higher thermal conductivity and lower phonon energies comparing with YAG, which determines those materials can be used in much higher power lasers with more efficiency. Up to now, the research on the Re sesquioxides focused on the Yb doped ones. In2009and2010, the high-power continuous-wave (cw) and femtosecond Yb:Lu2O3lasers have been reported to be149W and141W, respectively, which has indentified its promising applications.Besides the Yb doped materials, Nd doped crystals have also unique laser applications due to their abundant emission lines, such as about0.9μm,1.06μm and1.3μm, etc.. The Nd-doped sesquioxides has been proposed to be applied in Radar and eye-safe lasers. However, the Nd-doped sesquioxides are rarely investigated especially of their spectra and lasers, no matter whether in the crystalline or in the ceramic form, and the output powers are still very low. In this paper, the growth of Nd:Lu2O3single crystal by optical floating zone (OFZ) method was reported. The thermal peoperties, optical peoperties,and laser performance were also investigated detailedly. The main contents include:1. Growth of Nd:Lu2O3crystal. High quality Nd:Lu2O3crystal was successfully grown by Optical Floating-zone method. The factors influenced on crystal quality were also discussed. 2. Basic physical properties of Nd:Lu2O3crystal.X-ray powder diffraction(XRPD) was used to identify the structure and estimate the lattice parameter value of the as-grown crystal. The lattice parameter of Nd:Lu2O3is calculated to be1.0396nm, which approximates to the value of Lu2O3.The concentration of the Nd element in the as-grown crystal was measured by X-ray fluorescence (XRF) analyzer, and the effective segregation coefficient of Nd was determined to be0.7.The specific heat Cp was measured by using a thermal mechanical analyzer, and the results shows that heat capacity increases with the temperature increases. The thermal expansion was performed by a thermal mechanical analyzer, and the temperature dependence of theoretical density p was calculated. The thermal diffusivity λ of Nd:Lu2O3was measured by using a laser conductometer. Thermal conductivity of Nd:Lu2O3was calculated by using λ, ρ and Cp. At room temperature, thermal conductivity of Nd:Lu2O3is13.42W/mK, indicates that Lu2O3can be used as a promising host for Nd based high power laser systems.The absorption and emission spectrum of the crystal were measured at room temperature. J-O theory was used to calculate the optical parameters.2.81W cw dual-wavelength laser was obtained with an optical-optical efficiency of17%, and its wavelengths were centered at1076and1080nm. A maximum cw output power of142mW was obtained at951nm. |
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