Showing papers by "Li Li published in 2013"
TL;DR: A compact diode-pumped continuous wave and passively Q-switched Tm,Ho:LuLiF(4) laser is demonstrated and the pulse width and pulse energy are almost independent of the absorbed pump power.
Abstract: A compact diode-pumped continuous wave and passively Q-switched Tm,Ho:LuLiF(4) laser is demonstrated. The maximal output power of 381 mW at 2069 nm in continuous wave regime is obtained at an absorbed pump power of 1.5 W. By using a Cr(2+):ZnS saturable absorber, the maximum Q-switched average output power of 74 mW is obtained at 2055 nm. The pulse width and pulse energy are almost independent of the absorbed pump power, with the maximal values of 1.2 μs and of 13 μJ respectively. The pulse repetition frequency can be tuned almost linearly from 1 to 5.8 kHz by changing the absorbed pump power. Furthermore, a comparative analysis of laser performances with different output couplers is first carried out.
35 citations
TL;DR: A compact diode-end-pumped actively Q-switched intracavity Raman laser with Tm,Ho:GdVO( 4) laser gain medium and BaWO(4) Raman gain crystal is demonstrated for the first time.
Abstract: A compact diode-end-pumped actively Q-switched intracavity Raman laser with Tm,Ho:GdVO4 laser gain medium and BaWO4 Raman gain crystal is demonstrated for the first time. The Raman threshold is as low as 2.0 W of diode power at 802 nm. The highest average output power of 186 mW at the first Stokes wavelength of 2533 nm is obtained at a pulse repetition rate of 1 kHz, and a pump power of 2.8 W, corresponding to a diode-to-Stokes optical conversion efficiency of 6.6%. The pulsewidth and pulse energy are 7.8 ns and 0.19 mJ, respectively.
24 citations
01 Jan 2013
19 citations
TL;DR: In this article, a theoretical scheme for laser cooling of solids based on energy transfer usually found in rare-earth codoped materials is proposed. But the cooling scheme is not applicable to other rare earth (for example, Tm3+ and Er3+, or Er 3+ and Yb3+) materials.
Abstract: We report a theoretical scheme for laser cooling of solids based on energy transfer usually found in rare-earth codoped materials. The cooling scheme enables a large enhancement in the cooling efficiency with regard to the standard anti-Stokes fluorescence cooling. A Ho3+ and Tm3+-codoped low-phonon crystal (LiYF4) sample is investigated to find that the cooling efficiency increases, and then decreases with the increasing of the resonant absorption. The optimal cooling efficiency is predicted to exceed 5%. The maximum cooling power density could be promoted greatly by applying the codoped cooling scheme. The cooling scheme is also valid for other rare-earth (for example, Tm3+ and Er3+, or Er3+ and Yb3+) codoped materials.
18 citations
TL;DR: In this article, polydimethylsiloxane/poly (methyl methacrylates) copolymers (PDMS/PMMA) were synthesized by macromolecule initiation polymerization in the PDMS content (molar fraction) of 27.5%, 61.7%, 72.8% and 78%.
18 citations
TL;DR: The orthogonally polarized dual-wavelength single-longitudinal-mode laser is possible to be applied to the 2 μm differential absorption lidar and the generation of THz radiation.
Abstract: We first report a diode-pumped continuous wave orthogonally polarized dual-wavelength single-longitudinal-mode laser with a single c-cut Tm,Ho:LuLiF₄ laser crystal. The simultaneous dual-wavelength single-longitudinal-mode laser near 2 μm is realized by using two uncoated intracavity Fabry-Perot etalons. The output wavelengths are 2064 nm in π-polarization and 2066 nm in σ-polarization respectively, which are orthogonal to each other. At the absorbed pump power of 1 W, the maximum single-longitudinal-mode output powers at 2064 and 2066 nm are 76 and 32 mW respectively. The orthogonally polarized dual-wavelength single-longitudinal-mode laser is possible to be applied to the 2 μm differential absorption lidar and the generation of THz radiation.
17 citations
TL;DR: In this article, the upconversion spectra of Er 3+ doped ZrO 2 nanocrystals under different heat treating processes were analyzed and the mechanism of this phenomenon was attributed to the suppression of energy transfer from Er 3 + to OH −.
5 citations
Patent•
30 Jan 2013
TL;DR: In this article, the authors provided a nickel titanium memory alloy/polyurethane compound damping panel and a preparation method thereof, and the preparation method according to the invention comprises the following steps: placing a nickel Titanium memory alloy panel and polyurethANE panel into a hot press, and then pressing for 5-20min under the conditions of 185-195 DEG C temperature and 40-50 N pressure, and taking out and cooling in air.
Abstract: The invention provides a nickel titanium memory alloy/polyurethane compound damping panel and a preparation method thereof and relates to a compound damping panel and the preparation method thereof. The invention aims to solve the technical problems that the present surface layer is a 316L stainless steel compound steel panel, the tensile strength is low, the corrosion resistance is inferior and the present compound damping material has inferior damping effect. The preparation method according to the invention comprises the following steps: placing a nickel titanium memory alloy panel and a polyurethane panel into a hot press, and then pressing for 5-20min under the conditions of 185-195 DEG C temperature and 40-50N pressure, and taking out and cooling in air. The tensile strength of the compound damping panel provided by the invention is 600-800MPa; the precipitation volume of nickel ions in Nacl solution is 0.17ug/ml; the tensile strength is high; the corrosion resistance is excellent; a damping loss factor can reach 0.2; the vibration-reducing and noise-reducing effects are good; and the compound damping panel can be widely applied to passenger cars, trains, ships and buildings.
3 citations
Patent•
09 Jan 2013
TL;DR: The preparation process of champignon seasonings is described in this paper, where the ingredients are stored in an 80-mesh sieve for standby, and a rotary granulator is used for granulating.
Abstract: The invention relates to the field of seasonings, in particular to a preparation process of champignon seasoning. The preparation process comprises the following steps: baking champignon, then smashing the baked champignon and sieving the smashed champignon by a 80-mesh sieve for standby; pouring 30-40wt% of champignon powder, 5-10wt% of table salt, 5-10wt% of sodium glutamate, 0.1-1wt% of edible oil and 5-10wt% of sugar into a stirring machine for mixing and stirring; after stirring is performed for one hour, adding purified water which accounts for 4% of the total weight into the stirring machine, and continuing to stir for one hour until the materials are uniformly stirred; inputting the uniformly-stirred mixture into a rotary granulator and granulating; and inputting the granulated particles into a fluidized bed, drying the particles until the moisture content is less than 2%, performing vibration separation, packaging and storing the champignon seasoning into a warehouse. Since the technical scheme is adopted, no matter the champignon seasoning is produced at any season and any time, the quality can be ensured.
3 citations
10 Oct 2013
TL;DR: In this paper, a theoretical model involving the thermal radiation balance is established to discuss the intrinsic bistability of laser-induced thermal radiation, which is attributed to the nonlinear response of radiation quantum efficiency to local temperature.
Abstract: This paper presents the unusual bistable thermal radiation in rare earth doped solids under intense laser excitation. A theoretical model involving the thermal radiation balance is established to discuss the intrinsic bistability of laser-induced thermal radiation. The origin of thermal radiation bistability is attributed to the nonlinear response of radiation quantum efficiency to local temperature.
1 citations
10 Oct 2013
TL;DR: In this article, an upconversion-assisted anti-Stokes cooling scheme was proposed for Tm doped low phonon materials, where the up-conversion pumping from the metastable level to the excited level is introduced to produce extra anti-stokes cooling cycles which can improve the cooling performance.
Abstract: We present a physical scheme of upconversion-assisted anti-Stokes fluorescence cooling in Tm doped low phonon materials. The upconversion pumping from the metastable level to the upconversion excited level is introduced to produce extra anti-Stokes cooling cycles which can improve the laser cooling performance. Both the limitation of the cooling cryogenic temperature and the range of the cooling wavelength can be extended notably in contrast to the traditional anti-Stokes cooling.