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Record 217 of
Title:Spatiotemporal evolution of the light field inside the microresonator with normal dispersion
Author(s):Xu, Xin(1); Hu, Xiaohong(1); Feng, Ye(1); Liu, Yuanshan(1); Wang, Yishan(1); Wei, Ruyi(2)
Source: Guangxue Xuebao/Acta Optica Sinica Volume: 36 Issue: 6 DOI: 10.3788/AOS201636.0619001 Published: June 10, 2016
Abstract:Based on the Lugiato-Lefever equation, the spatiotemporal evolutions in microresonator are discussed respectively, which is pumped by the continuous wave (CW) light as well as the combination of CW light and periodical pulse train simultaneously, and the effect of each parameter on light field is studied. Simulation results indicate that the dark soliton can exist in the microresonator with CW pumped. The width of the dark soliton pulse increases with the dispersion coefficient. The shape of the dark soliton pulse is varied when the frequency detuning is increased. Meanwhile, in the normal dispersion regime, the pulses can form in the microresonator by the use of synthetical pumping manner. The drawback is compensated that the bright soliton pulse is difficult to be generated in the microresonator for single CW pumped of certain parameters configuration. Moreover, the high amplitude of the pump pulses leads to the pulse split, the pulse stretching and the loss of the pulse occur when the frequency detuning of the microresonator rises. Theoretical analysis results are significant for high-quality Kerr optical frequency comb and their practical applications, and they are helpful for selecting the proper microresonator and pump parameters. ? 2016, Chinese Lasers Press. All right reserved.
Accession Number: 20162502529803
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Record 218 of
Title:Systematic experimental study on a highly efficient terahertz source based on two-color laser-induced air plasma
Author(s):Xie, Jun(1,2); Fan, Wen-Hui(1); Chen, Xu(1,2)
Source: Laser Physics Volume: 26 Issue: 5 DOI: 10.1088/1054-660X/26/5/055002 Published: May 2016
Abstract:In this paper, highly efficient terahertz radiation generated by two-color femtosecond laser-induced air plasma is reported. A number of variables that can obviously influence terahertz generation and detection have been investigated systematically. The dependence on experimental parameters, including pulse energy, the rotation angle of beta-barium boron oxide (BBO) crystal, the distance between BBO crystal and laser-induced plasma, focal length, chopper frequency, and detection angle are presented, and the optimal values of these parameters have also been obtained experimentally. Finally, a highly efficient terahertz source has been achieved and can be utilized to carry out further investigation on terahertz sensing, spectroscopy, and imaging. ? 2016 Astro Ltd.
Accession Number: 20161902348200
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Record 219 of
Title:High-Quality Hollow Closed-Pore Silica Antireflection Coatings Based on Styrene-Acrylate Emulsion @ Organic-Inorganic Silica Precursor
Author(s):Guo, Zhaolong(1,2); Zhao, Haixin(1); Zhao, Wei(1); Wang, Tao(1); Kong, Depeng(1); Chen, Taojing(1); Zhang, Xiaoyan(1)
Source: ACS Applied Materials and Interfaces Volume: 8 Issue: 18 DOI: 10.1021/acsami.6b02192 Published: May 11, 2016
Abstract:Making use of a facile and low-cost way for the preparation of a hierarchically organized novel hollow closed-pore silica antireflective coating (CHAR) with tailored optical properties and a mechanical reliability is of great interest in the field of solar photovoltaic technology. The process mainly contains two aspects: (1) a styrene-acrylate emulsion @ organic-inorganic silica precursor (SA@OISP) core/shell hierarchical nanostructure, consisting of a sacrificial styrene-acrylate (SA) primary template, was fabricated using a sol-gel method; (2) the self-assembly of the nanostructures leads to SA@OISP nanospheres forming the high-quality hollow closed-pore silica antireflection coating (CHAR) by a dip-coating process and a subsequent calcination treatment. The resulting SA@OISP nanospheres have a mean diameter of 65.2 nm and contained a SA soft core with a mean diameter of approximately 54.8 nm and an organic-inorganic silica precursor (OISP) shell with a thickness of approximately 6-10 nm. Furthermore, the prepared CHAR film exhibited a high transmittance and good ruggedness. An average transmittance (TAV) of 97.64% was obtained, and the value is close to the ideal single-layered antireflection coating (98.09%) over a broad range of wavelengths (from 380 to 1100 nm). The CHAR film showed a stable TAV, with attenuation values of less than 0.8% and 0.43% after the abrasion test and the damp heat test, respectively. The conversion efficiency of the CHAR coating cover solar modules tends to be increased by 3.75%. The promising results obtained in this study suggest that the CHAR film was considered as an essential component of the solar module and were expected to provide additional solar energy harvest under extreme outdoor climates. ? 2016 American Chemical Society.
Accession Number: 20162502514521
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Record 220 of
Title:Terahertz emission dependence on the polarization angle between two-color lasers
Author(s):Xie, Jun(1,2); Fan, Wen-Hui(1); Tang, Jie(1)
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 45 Issue: 10 DOI: 10.3788/gzxb20164510.1030002 Published: October 1, 2016
Abstract:The influence of the polarization angle between two-color lasers on the Terahertz (THz) emission was investigated based on a modified two-dimensional transient current model. By changing the polarization angle between the fundamental frequency laser and its second harmonic laser beam, it is found that, the emitted THz amplitude varys periodically with the chaning of the polarization angle in laser plasma, and the optimal angle is also changed with the different laser intensity. Under the comparatively low laser intensity (≤2×1014W/cm2), the THz amplitude can reach the maximum when the two-color lasers have the same polarization. However, the optimal angle will increase with the increasing of the total laser intensity when the laser intensity is high enough(>2×1014W/cm2). The electron density was firstly used to analyze this phenomenon under comparatively low laser intensity and then the residual drift current was utilized to reveal the underlying physical mechanism. It was found that, the residual current density is the essential source of the THz waves and which can determine the intensity of THz emission ? 2016, Science Press. All right reserved.
Accession Number: 20164302952423
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Record 221 of
Title:Optical microfiber knot resonator (MKR) and its slow-light performance
Author(s):Ren, Liyong(1); Xu, Yiping(1,2); Ma, Chengju(1,2); Wang, Yingli(1); Kong, Xudong(1,2); Liang, Jian(1); Ju, Haijuan(1); Ren, Kaili(1,2); Lin, Xiao(1,2)
Source: Journal of Physics: Conference Series Volume: 680 Issue: 1 DOI: 10.1088/1742-6596/680/1/012032 Published: February 3, 2016
Abstract:null
Accession Number: 20161802335954
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Record 222 of
Title:Optical design of infrared diffractive telescope
Author(s):Wang, Hao(1,2); Kang, Fu-Zeng(1); Zhao, Wei(1); Xie, Yong-Jun(1)
Source: Hongwai Yu Haomibo Xuebao/Journal of Infrared and Millimeter Waves Volume: 35 Issue: 4 DOI: 10.11972/j.issn.1001-9014.2016.04.008 Published: August 1, 2016
Abstract:A design example of diffractive telescope is presented and the aperture of objective is 3 meters. The operating wavelength of the system is 7.7~10.3 μm and spectral bandwidth |Δλ/λ| is about 1/3. It is shown that the system approximately attains diffraction limit. We developed a small scale diffractive telescope and its' image quality was perfect. ? 2016, Science Press. All right reserved.
Accession Number: 20163702784838
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Record 223 of
Title:Broadband and efficient wavelength conversion in a slot-width switching silicon-organic hybrid waveguide
Author(s):Bai, Xinxin(1); Liu, Hongjun(1); Sun, Qibing(1); Huang, Nan(1); Wang, Zhaolu(1)
Source: Journal of Modern Optics Volume: 63 Issue: 3 DOI: 10.1080/09500340.2015.1073809 Published: February 4, 2016
Abstract:We propose a slot-width switching (SWS) silicon-organic hybrid waveguide for broadband and efficient wavelength conversion. By switching the slot width of different lengths, the quasi-phase-matching can be obtained. Compared with width-modulated silicon-on-insulator (SOI) waveguide, the non-linear absorption can be ignored in slot waveguide which is filled with p-toluene sulphonate. Consequently, the conversion efficiency at a particular signal wavelength is improved, and the 3-dB conversion bandwidth is also extended. The numerical simulation results indicate that, for a continuous-wave pump at 1550 nm, a conversion bandwidth of 570 nm and a peak conversion efficiency of 11.32 dB can be realized in a 7.5-mm-long SWS waveguide, which is better than that of width-modulated SOI waveguide. ? 2015 Taylor and Francis.
Accession Number: 20153201119391
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Record 224 of
Title:Research of LD-pumped passively Q-switched Yb:YAG thin disk laser
Author(s):Wang, Xu(1,2); Cheng, Guang-Hua(1); Sun, Zhe(1)
Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 45 Issue: 3 DOI: 10.3788/gzxb20164503.0314009 Published: March 1, 2016
Abstract:Using 940 nm diode laser as pumping source, a passively Q-switched Yb:YAG thin disk laser by Cr4+:YAG was realized. The Yb:YAG disk with 500 μm thickness was employed, the Yb3+ atom fraction is 10%. The distribution of temperature in Yb:YAG disk with direct water cooling and SiC cooling with different thickness was theoretically simulated, respectively. The maximum output power of 2.8 W at 1030 nm was obtained with 800 μm SiC cooling, the output power has increased by 40% than that obtained with direct water cooling. The initial transmission of Cr4+:YAG crystal and the output coupling rate were optimized by Degnan's theory. With the initial transmission of Cr4+:YAG crystal of 93% and the output coupling rate of 10%, a stable pulse train of 1.95 W averaged output power with a pulse energy of 1.2 mJ and pulse width of 74 ns were obtained with 800 μm SiC cooling. The repetition rate is 1.6 kHz, the slope efficiency is 18.1%, and the beam quality Mx2=1.622, My2=1.616. ? 2016, Science Press. All right reserved.
Accession Number: 20161602269773
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Record 225 of
Title:Polarization-insensitive tunable multiple electromagnetically induced transparencies analogue in terahertz graphene metamaterial
Author(s):Chen, Xu(1,2); Fan, Wenhui(1)
Source: Optical Materials Express Volume: 6 Issue: 8 DOI: 10.1364/OME.6.002607 Published: 2016
Abstract:A graphene-based metamaterial structure composed of multilayer graphene/dielectric stacking configuration is proposed, which achieves multiple analogue of electromagnetically induced transparencies (EIT) effect at terahertz frequencies. Using the phase-coupling scheme, a theoretical model is established to study the EIT-like effect of the proposed structure, and the theoretical calculations coincide well with the numerical simulated results. By varying the Fermi energy level of the graphene, the EIT-like windows can be dynamically tuned in a wide range of terahertz spectra. Particularly, since the symmetry of the structure, the EIT-like effect is polarization-insensitive and can be performed very well in a large incident angles, nearly 80° for both transverse electric and transverse magnetic waves. The proposed structure has potential applications in tunable terahertz chipintegrated optical devices, especially for dynamic multi-band filters, sensors, modulators and nonlinear devices. ? 2016 Optical Society of America.
Accession Number: 20163502762278
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Record 226 of
Title:Spinning and orbiting motion of particles in vortex beams with circular or radial polarizations
Author(s):Li, Manman(1,2); Yan, Shaohui(1); Yao, Baoli(1); Liang, Yansheng(1); Zhang, Peng(1)
Source: Optics Express Volume: 24 Issue: 18 DOI: 10.1364/OE.24.020604 Published: September 5, 2016
Abstract:Focusing fields of optical vortex (OV) beams with circular or radial polarizations carry both spin angular momentum (SAM) and orbital angular momentum (OAM), and can realize non-axial spinning and orbiting motion of absorptive particles. Using the T-matrix method, we evaluate the optical forces and torques exerted on micro-sized particles induced by the OV beams. Numerical results demonstrate that the particle is trapped on the circle of intensity maxima, and experiences a transverse spin torque along azimuthal direction, a longitudinal spin torque, and an orbital torque, respectively. The direction of spinning motion is not only related to the sign of topological charge of the OV beam, but also to the polarization state. However, the topological charge controls the direction of orbiting motion individually. Optically induced rotations of particles with varying sizes and absorptivity are investigated in OV beams with different topological charges and polarization states. These results may be exploited in practical optical manipulation, especially for optically induced rotations of micro-particles. ? 2016 Optical Society of America.
Accession Number: 20164002875387
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Record 227 of
Title:Non-invasive investigation of microstructure of ding kiln porcelain with optical coherence tomography
Author(s):Yang, Shanshan(1,2); Mi, Lei(1); Zhu, Rui(1,2); Liu, Haiping(2)
Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 43 Issue: 2 DOI: 10.3788/CJL201643.0208002 Published: February 10, 2016
Abstract:Optical coherence tomography (OCT) is a non-destructive subsurface tomography system based on low coherence interferometry. Non-invasive nature and high speed of acquisition of OCT make it possible to image relic and provide subsurface morphology visualization. Porcelain from Ding kiln of Northern Song Dynasty is scanned and imaged to visualize the subsurface morphology of the surface glaze and core. Layer structures and interfaces can be visualized clearly from OCT images. The characteristics of the thickness of the glaze layer, bubbles and crystal particles in glaze, the penetration depth of OCT in porcelain are analyzed. ? 2016, Chinese Laser Press. All right reserved.
Accession Number: 20161202115003
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Record 228 of
Title:High repetition rate and short pulse width electro-optic Q-switched Nd:YVO4 laser
Author(s):Wang, Xu(1,2); Sun, Zhe(1); Cheng, Guanghua(1)
Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 43 Issue: 6 DOI: 10.3788/CJL201643.0601007 Published: June 10, 2016
Abstract:Using the rubidium oxygen titanium phosphate (RTP) electro-optic deflector as a Q-switch, we realize a continuous wave LD-pumped Q-switched Nd:YVO4 laser and study the output characteristics in experiments at different output coupling rates and different repetition rates. An output pulse train of 1.22 W average output power with pulse width of 1.0 ns and peak power of 224 kW is obtained at the repetition rate of 5 kHz and an output coupler with transmittance of 60%. Another out pulse of 2.67 W average output power with pulse width of 2.2 ns and peak power of 60.7 kW is obtained when the repetition rate is 20 kHz, the slope efficiency is 37%, and the beam quality factors are Mx2=1.226, My2=1.229. Further, by extra-cavity double-frequency based on a potassium titanium oxide phosphate (KTP) crystal, a green laser at 532 nm with repetition rate of 20 kHz and average output power of 1.33 W is obtained, and the corresponding frequency-doubling efficiency is 50%. ? 2016, Chinese Lasers Press. All right reserved.
Accession Number: 20162502529823
