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Record 181 of
Title:Fundamental-frequency-absorbed oxyfluoride glass in a high-power laser
Author(s):Hou, Chaoqi(1); Li, Weinan(1); Pengfei, Wang(1); Lu, Min(1); Bo, Peng(1); Haitao, Guo(1); Fei, Gao(1); Xiaoxia, Cui(1)
Source: Applied Optics Volume: 55 Issue: 10 DOI: 10.1364/AO.55.002649 Published: April 1, 2016
Abstract:A high-power third-harmonic laser faces challenges in the filtering remnant unconverted fundamental frequency, which is from the frequency converting crystal. In this work, a novel fundamental-frequency-absorbed oxyfluoride glass has been prepared, which provides a possible option to solve the problem. By being doped with Fe2 ion, the glass shows strong absorption property at 1053 nm, and the glass's transmittances at 351 and 1053 nm are stable with changing the laser power or increasing the irradiation times under high-power laser irradiation. Meanwhile, the laser-induced damage threshold of the glass is 12.5 J/cm2 at 351 nm, which is two times higher than that of fused silica whose threshold is 6.2 J/cm2 in the same testing condition. The glass also exhibits a higher laserinduced damage threshold as well as 36.6 J/cm2 at its absorption wavelength of 1053 nm. The results indicate that this glass is promising as a color-separation optic, thus allowing a novel design for the final optics assembly in an inertial confinement fusion laser system. ? 2016 Optical Society of America.
Accession Number: 20161502227914
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Record 182 of
Title:KW-level low photodarkening Yb/Ce codoped aluminosilicate fiber fabricated by the chelate gas phase deposition technique
Author(s):Zhang, Lihua(1); Li, Gang(1); Li, Weinan(1); Gao, Qi(1); Li, Zhe(1); Zhao, Wei(1); Zhao, Baoyin(1); Hou, Chaoqi(1)
Source: Optical Materials Express Volume: 6 Issue: 11 DOI: 10.1364/OME.6.003558 Published: 2016
Abstract:A Yb/Ce codoped aluminosilicate fiber was successfully fabricated by the chelate gas phase deposition technique. Using the homemade fiber as the amplifier stage in a master oscillator power amplifier configuration laser setup, a near single mode laser output (M2 = 1.55) with an output power of 1026 W and slope efficiency of 84.8% is obtained. In the 100 hour photodarkening experiment, the entire reduced power is less than 14 W, and the ratio, compared to the initial 1026 W output power, is less than 1.4%. The investigation of optical properties indicates that Yb/Ce codoped aluminosilicate fiber fabricated by the chelate gas phase deposition technique shows homogenous distribution, appropriate absorption coefficient, low background attenuation, high optical-to-optical efficiency and a rather low photodarkening loss, making it a promising candidate as an active fiber for a reliable and efficient fiber laser in high-power applications. ? 2016 Optical Society of America.
Accession Number: 20164603012282
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Record 183 of
Title:Optical properties and Judd-Ofelt analysis of a novel europium pentafluoropropionate complex with 2,2′-bipyridine
Author(s):Li, Dong-Dong(1,2); She, Jiang-Bo(2); Nie, Rong-Zhi(2); Peng, Bo(2)
Source: Optik Volume: 127 Issue: 4 DOI: 10.1016/j.ijleo.2015.11.130 Published: February 1, 2016
Abstract:Europium pentafluoropropionate 2,2′-bipyridine complex, Eu(C2F5COO)3·bpy (bpy = 2,2′-bipyridine), were synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TA).The excitation spectra of the complex demonstrate that the energy collected by "antenna ligands" was transferred to Eu3+ ions efficiently. The room-temperature PL spectra of the complex is composed of the typical Eu3+ ions red emission, due to transitions between 5D0 → 7FJ(J=0→4). The lifetimes of 5D0 of Eu3+ in the complex were examined using time-resolved spectroscopic analysis, and the lifetime values of Eu(C2F5COO)3·bpy were fitting with monoexponential (2585 μs) curve. The decomposition temperature of the complex was 262 °C, which indicates the host complex was quite stable to heat. According to the fluorescence emission spectra, the Judd-Ofelt parameters Ω2, Ω4 of the complexes were calculated and the radiative properties were also presented. The 5D0 radiative lifetime, quantum yield and the stimulated emission cross-section of the complex is excellent, which prove that this complex will be promising material for laser application. ? 2015 Elsevier GmbH.
Accession Number: 20160301806145
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Record 184 of
Title:Thermal management technology of a liquid cooling thin-disk oscillator
Author(s):Yang, Peng(1); L., Ma; Y.-L., Jiang; W., Li; R.-Z., Nie; P.-F., Zhao; J.-B., She
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 45 Issue: 3 DOI: 10.3788/gzxb20164503.0314007 Published: March 1, 2016
Abstract:In order to solve the problem of the thermal effect of the laser gain media, a configuration named "immersed thin-disk oscillator" solid laser cooled directly with flow was proposed. Under the repeated pumping frequency of 10 Hz, a maximum output energy of 615mJ was realized. The optical-optical efficiency and the slope efficiency is 23% and 21% respectively. Based on the principle of fluid mechanics and thermodynamics, the thermal-flow-solid coupling model of lasing region was established. By using the software and the method of finite element analysis, the distribution characteristics of temperature field and velocity field were studied under the conditions of different flow rate and pump power. The wavefront aberration of the laser passing the gain region was simulated under the condition of liquid-cooled. The maximum optical path difference of the gain medium and coolant liquid are 0.7666λ and -4.7331λ respectively. The results show that the laser has a good thermal management performance. ? 2016, Science Press. All right reserved.
Accession Number: 20161602269771
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Record 185 of
Title:Simulation of the electron collection efficiency of a PMT based on the MCP coated with high secondary yield material
Author(s):Chen, Lin(1,2,4,5); Tian, Jinshou(1,5); Zhao, Tianchi(3); Liu, Chunliang(4); Liu, Hulin(1); Wei, Yonglin(1); Sai, Xiaofeng(1); Chen, Ping(1,2); Wang, Xing(1); Lu, Yu(1); Hui, Dandan(1,2)
Source: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 835 Issue: DOI: 10.1016/j.nima.2016.08.034 Published: November 1, 2016
Abstract:Owning to the serious loss of photoelectrons striking at the input electrode of traditional microchannel plate (MCP), photoelectron collection efficiency (CE) of photomultiplier tubes based on MCP (MCP-PMTs) fluctuates around the MCP open area fraction and cannot make a breakthrough. Depositing a thin film of high secondary electron yield material on the MCP is proposed as an effective approach to improve the CE. The available simulation and experimental data to validate it, however, is sparse. In our work, a three-dimensional small area MCP model is developed in CST Studio Suite to evaluate the collection efficiencies of PMTs based on the traditional MCP and the coated one, respectively. Results predict that CE of the PMT based on the coated MCP has a significant increase and a better uniformity, which is expected to reach 100%. ? 2016 Elsevier B.V.
Accession Number: 20164102887296
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Record 186 of
Title:Optical micro-manipulation based on spatial modulation of optical fields
Author(s):Liang, Yansheng(1); Yao, Baoli(1); Lei, Ming(1); Yan, Shaohui(1); Yu, Xianghua(1); Li, Manman(1)
Source: Guangxue Xuebao/Acta Optica Sinica Volume: 36 Issue: 10 DOI: 10.3788/AOS201636.1026003 Published: October 10, 2016
Abstract:Optical tweezers has become a powerful tool for research in life science and colloidal physics since its invention due to its advantages of mechanical contact-free and high-precision manipulation of micro-sized particles. However, the conventional single-trap optical tweezers is limited in the increasing demands of research. In recent years, the technique of spatial modulation of optical fields, which modulates the amplitude, phase and polarization state of light, has extensively enhanced the function of optical micro-manipulation, and promoted the advance in laser micro/nano fabricaton, optical sorting and transportation of micro-particles, and colloidal particles studies. The advance in spatial modulation of optical fields to date and their applications in optical micro-manipulation is reviewed, including the holographic optical tweezers, special-mode optical beams manipulation, and vector beams manipulation. ? 2016, Chinese Lasers Press. All right reserved.
Accession Number: 20164502988927
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Record 187 of
Title:Analysis of the influence of nanofissure morphology on the performance of surface-conduction electron emitters
Author(s):Shen, Zhihua(1); Wang, Xiao(1); Wu, Shengli(1); Tian, JinShou(2)
Source: Journal of Micromechanics and Microengineering Volume: 26 Issue: 4 DOI: 10.1088/0960-1317/26/4/045011 Published: March 11, 2016
Abstract:A simulation model was built to numerically investigate the electron emission property of a new surface-conduction electron emitter (SCE) with a raised emitter structure. The model calculated the electric field distribution, the electron emission characteristics, and the electron trajectories, which were useful for analyzing and understanding the microscopic mechanism of the electron emissions of the new SCE structure. It was found that the new structure increased the probability of electrons being collected by the anode which led to an increase of the anode current despite of the decrease of field emission current. This study benefits the advanced design of emitter structures in nanoscale technology for new types of electron sources. ? 2016 IOP Publishing Ltd.
Accession Number: 20161502213267
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Record 188 of
Title:Near infrared quantum cutting of Tb3+-Yb3+ co-doped CeF3 nanophosphors
Author(s):Sun, Xiao(1); Hu, Xiao-Yun(1,2); Hou, Wen-Qian(3); Fan, Jun(3); Miao, Hui(1); Zhan, Su-Chang(1)
Source: Journal of Nanoscience and Nanotechnology Volume: 16 Issue: 4 DOI: 10.1166/jnn.2016.11880 Published: April 2016
Abstract:In this paper, Tb3+-Yb3+ Co-doped CeF3 nanophosphors were synthesized using the microwave-assisted heating hydrothermal method (M-H). The excitation and emission spectra of the samples at room temperature show that the samples absorb ultraviolet light from 250 nm to 280 nm, and emit light at 300 nm. This corresponds to the transitions from 5D to 4F of Ce3+, 480 nm, 540 nm, 583 nm, 620 nm which correspond to the transitions from 5D4 to 7F6, 5, 4, 3 of Tb3+, 973 nm which corresponds to the transitions from 2F5/2-2F7/2 of Yb3+. In the emission spectra, it is clear that the emission intensity of Ce3+ and Tb3+ decreases, and Yb3+ increases with increasing Yb3+. This suggests that energy transfer from Ce3+ to Yb3+, and Ce3+ to Tb3+ to Yb3+ may occur. In the near infrared emission area, it is noted that a distinct emission centered at 973 nm was observed under 260 nm excitation. This is due to transitions among the different Stark levels of 2FJ(J=5/2, 7/2) Yb3+ ions. This also suggests an energy transfer from Ce3+ ions to Tb3+ and then to Yb3+. The energy transfers from Tb3+-Yb3+ Co-doped CeF3 nanophosphors, which lead to intense NIR emissions at 900-1050 nm, match the energy of Si band gaps of Si-based solar cells. Therefore, these kinds of materials are promising candidates for applications that require modifying if solar spectrums and enhancement of conversion efficiency of Si-based solar cells. Copyright ? 2016 American Scientific Publishers All rights reserved.
Accession Number: 20162302462755
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Record 189 of
Title:Research on temperature tuning properties of chirped fiber grating
Author(s):Zhang, Xin(1); Yang, Zhi(1); Li, Qianglong(1); Li, Feng(1); Yang, Xiaojun(1); Wang, Yishan(1); Zhao, Wei(1)
Source: Guangxue Xuebao/Acta Optica Sinica Volume: 36 Issue: 5 DOI: 10.3788/AOS201636.0505002 Published: May 10, 2016
Abstract:According to the temperature tenability of chirped fiber grating, the minimum output pulse width can be obtained by controlling the fiber grating's temperature to change the dispersion of the chirped fiber grating, and the feasibility of this idea is demonstrated through experiments. The chirped fiber grating is used as the stretcher in the fiber chirped pulse amplification (CPA) system, and the gratings-pair is used as compressor. The positive dispersion brought by the stretcher is compensated by the negative dispersion provided by the compressor. The output pulse width is measured by the auto-correlation for denoting the dispersion of the chirped fiber Bragg grating indirectly as a function of temperature. It can be seen from the obtained experimental data that, when the temperature rises from -7℃ to 50℃, the pulse width falls from 1057 fs to 764 fs, and then rises to 910 fs, with a total change of 439 fs achieved. In the experiment, dispersion increases with temperature rising, changing from insufficient dispersion compensation to over dispersion compensation. ? 2016, Chinese Lasers Press. All right reserved.
Accession Number: 20162102427137
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Record 190 of
Title:Effect of fabrication errors of double-layer BOE on diffractive efficiency
Author(s):Ma, Zebin(1); Kang, Fuzeng(1); Wang, Hao(1)
Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 45 Issue: 9 DOI: 10.3788/IRLA201645.0918001 Published: September 25, 2016
Abstract:With the development of optical technology, optic-mechanical-electric technology becomes a trend. An integrated, arrayed and miniaturized optical system was required. Binary optical element is famous for its excellent performance in light-wave transformation. Double-layer binary optical element has high diffraction efficiency over wide wavelength range. However, in the fabrication of double layer BOE, many errors occurred, such as height error, periodic error, multi-mask fabrication error etc.A theoretical analysis of these errors was carried out based on scalar diffraction theory, and a MATLAB simulation was implemented. The simulation result indicated that the diffraction efficiency deteriorated if the height errors occurred in different direction rather than in the same direction. Therefore, height errors from different direction should be avoid in fabrication. If the multi-mask fabrication error is occurred from different direction, the diffraction efficiency will decrease more quickly than from the same direction, so multi-mask fabrication error from different direction should be avoid as much as possible. Compared to height error and multi-mask fabrication error, other four errors have varying degrees of impact on the diffraction efficiency. ? 2016, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.
Accession Number: 20164302952475
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Record 191 of
Title:Numerical calculation of 3.8 μm and 1.55 μm laser radiation transmission characteristic under foggy condition
Author(s):Zhang, Zeyu(1,2); Xie, Xiaoping(1); Duan, Tao(1); Wen, Yu(3); Wang, Wei(1)
Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 45 Issue: DOI: 10.3788/IRLA201645.S104007 Published: May 25, 2016
Abstract:Fog is an inevitable weather factor affecting the performance of free space optical communication. Selecting the appropriate laser wavelength can effectively reduce the influence. Three atmospheric visibility of mist, fog, haze were considered in this paper. The transmission characteristic of mid-wave IR wavelength at 3.8 μm was compared with the traditional near-infrared wavelength at 1.55 μm that both belong to atmospheric transmission windows. Using Monte Carlo method, the propagation of a large number of photons along the horizontal direction was numerically simulated. Relationship between the relative light intensity and different receiving surface radius, photon transmittance under different transmission distance and different atmospheric visibility were worked out. The result reveals that the mid- wave IR wavelength at 3.8 μm, the light intensity is more concentrated under the same radius of receiving surface, and photon transmission is higher under the same propagation distance and less affected by atmospheric visibility. The wavelength at 3.8 μm is more suitable for horizontal link of free space optical communication in the fog than 1.55 μm. ? 2016, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.
Accession Number: 20162502515417
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Record 192 of
Title:Effects of fluorine on the properties of Yb/Ce co-doped aluminosilicate preforms prepared by MCVD with organic chelate precursor doping technique
Author(s):Li, Weinan(1); Luo, Rong(1); Li, Chao(1); Gao, Song(1); Chang, Chang(1); Hou, Chaoqi(1); Zhao, Baoyin(1)
Source: Journal of Non-Crystalline Solids Volume: 449 Issue: DOI: 10.1016/j.jnoncrysol.2016.07.016 Published: October 1, 2016
Abstract:Co-doped Yb/Ce aluminosilicate fiber preforms with less than 1 Wt% fluorine were prepared by MCVD with organic chelate precursor doping technique at 1400 °C. Fluorine content characterized by electron probe microanalysis decreased with increasing SiF4 flow and flow ratio of SiF4/SiCl4. Under maximum SiF4 flow the concentrations of Yb2O3 and CeO2 in the perform core were only as much as 17% and 25% under minimum SiF4 flow, respectively, but smaller refractive index change was only shown in fiber core. The reason was that the reaction of SiF4 with Al2O3,Yb2O3,CeO2 were intensified with increasing flow ratio of SiF4/SiCl4 and then resulted in producing more exhaust gas such as AlF3, YbF3 and CeF4. Raman spectra of core glasses with ? 1 of [Formula presented] stretching bond was not observed, and with growth of fluorine content antisymmetric stretching vibrations of Si-O-Si linkages split from an envelope of 1188 cm? 1 into two peaks or three peaks shifted higher frequency. At the same time, Boson peak near 125 cm? 1 shifted to lower frequency. They were attributed to some minor changes of glass's network structure due to introducing lower fluorine into core glasses. On base of bonding energy measured by X-ray photoelectric spectroscopy, the plane graph describing the complex bonding distribution with F in core was supplied to in order to illustrate network structure change. ? 2016 Elsevier B.V.
Accession Number: 20163002639631
