2019
2019
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Record 13 of
Title:Feasibility of Satellite-borne Wind Observations of Stratosphere and Mesosphere Based on the Emission Line O19P18 of O2(a1Δg)
Author(s):Feng, Yu-Tao(1); Wu, Kui-Jun(2); Fu, Di(1); Hao, Xiong-Bo(1); Wu, Jun-Qiang(1); Fu, Jian-Guo(3); Hu, Bing-Liang(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 48 Issue: 2 DOI: 10.3788/gzxb20194802.0201001 Published: February 2019Abstract:The main propose of this paper is to discuss the possibilities and advantages of satellite-bornelimb-viewing for wind observations of stratosphere and mesosphere based on the emission line O19P18 of O2(a1Δg)O19P18(7 772.03 cm-1). The radiative transfer model of O2(a1Δg, υ'=0)→O2(X3Σg,υ"=0) is constructed based on atmosphere model and radiative transfer theory. Furthermore, multiple scattering radiative transfer and nonlocal thermal equilibrium (non-LTE) models are taken into consideration in the simulation of spectrum from limb-viewing. The emission line O19P18 (7 772.030 cm-1) with weak self-absorption, bright radiation intensity and large spectral separation range is proved to be suitable for limb-viewing wind detection. Applying the emission line O2(a1Δg)O19P18 for wind observation gets low requirement of spectral resolution and full width of half maxima of filter, making the satellite loading much more possible to be miniaturization and stabilization. The O2(a1Δg)O19P18(7 772.03 cm-1) based Doppler asymmetric spatial heterodyne interferometer technique scheme is also proposed in this paper.The simulation of limb-viewing wind measurement by proposed scheme indicates that wind measurement precision is better than 5 m/s over an altitude range of 40 to 70 km in general. In the low precision requirement condition, the measurement range could reach lower than 40km. The research achievement of this paper could provide the low cost, high precision, independent technique approach for stratosphere and mesosphere wind measurement. ? 2019, Science Press. All right reserved.Accession Number: 20191806866971 -
Record 14 of
Title:Continuously tunable orthogonally polarized RF optical single sideband generator based on cascaded micro-ring resonators
Author(s):Zhang, Yuning(1); Xu, Xingyuan(1); Wu, Jiayang(1); Jia, Linnan(1); Tan, Mengxi(1); Nguyen, Thach G.(2); Chu, Sai T.(3); Little, Brent E.(4); Morandotti, Roberto(5,6,7); Mitchell, Arnan(2); Moss, David J.(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11200 Issue: DOI: 10.1117/12.2540180 Published: 2019Abstract:We demonstrate an orthogonally polarized optical single sideband (OP-OSSB) generator based on dual cascaded micro-ring resonators (MRRs). We achieve a large tuning range of the optical carrier to sideband ratio of up to 57.3 dB. The operation RF frequency of the OP-OSSB generator can also be continuously tuned with a 21.4 GHz range via independent thermal control of the two MRRs. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20200808205244 -
Record 15 of
Title:Thermal Stability Analysis and Experimental Study of a New Type of Grid-Reinforced Carbon Fiber Mirror
Author(s):Xu, Liang(1); Ding, Jiaoteng(1); Wang, Yongjie(1); Xie, Yongjie(1); Wu, Xiaoge(1); Ma, Zhen(1)Source: Applied Composite Materials Volume: 26 Issue: 2 DOI: 10.1007/s10443-018-9705-1 Published: April 15, 2019Abstract:Due to low density, high specific stiffness, and low thermal expansion, carbon fiber reinforced plastic (CFRP) is one of potential materials for high precise components. For high precise structures such as reflectors and optical mirrors, usually strict thermal stability required. In order to ensure rigidity and thermal deformation resistance, carbon fiber mirrors are usually designed as a grid-reinforced sandwich structure. In order to improve the thermal stability of carbon fiber mirrors, a new type of grid-reinforced sandwich structure design is proposed. Finite element method was used to analyze the thermal deformations of the carbon fiber mirror without manufacturing error and with manufacturing error. In order to overcome the effect of moisture absorption deformation, thermal deformation test of the carbon fiber mirror was performed in a vacuum tank. The test results verify the reliability of the finite element analysis results. For Φ100mm center aperture of the Φ150mm carbon fiber mirror, the test results show that the thermal stability is about 4?nm/°C, which is enough for optical mirror application, although "grid effect" existed. ? 2018, Springer Science+Business Media B.V., part of Springer Nature.Accession Number: 20182305282407 -
Record 16 of
Title:All-Fiber Saturable Absorbers for Ultrafast Fiber Lasers
Author(s):Zhao, Wei(1,2); Chen, Guangwei(1,2,3); Li, Wenlei(1,2,4); Wang, Guomei(1,2,5); Zeng, Chao(1,2)Source: IEEE Photonics Journal Volume: 11 Issue: 5 DOI: 10.1109/JPHOT.2019.2941580 Published: October 2019Abstract:The past decade has witnessed tremendous achievements of ultrafast fiber laser technologies due to rapid developments of saturable absorbers (SAs) based on, in particular, nanomaterials such as 0D quantum dot, 1D carbon nanotubes, 2D layered materials, and 3D nanostructures. However, most of those nanomaterials-based SAs are inevitably absence of the high damage threshold and all-fiber integration, therefore challenging their applications on highly integrated and high-energy pulse generations. Recently, the real all-fiber SAs based on the nonlinear multimodal interference (NLMMI) technique using multimode fibers are demonstrated to overcome the above limitations. In this review, a detailed summary of the recent advances in NLMMI-based all-fiber SAs is provided, including the fundamental theory, implementation scenarios, and ultrafast fiber lasers of the all-fiber SAs, covering wide wavelength range of 1, 1.55, and 2 μm. In addition to the state-of-the-art overview, optical rogue waves in the all-fiber SA-based ultrafast fiber laser are extensively analyzed, which reveals the laser physics behind the dynamics from low-energy to high-energy pulses and directs the design of high-energy ultrafast fiber lasers. The conclusions and perspectives of the all-fiber SAs are also discussed at the end. ? 2009-2012 IEEE.Accession Number: 20200308031152 -
Record 17 of
Title:Ultrahigh-Q toroidal dipole resonance in all-dielectric metamaterials for terahertz sensing
Author(s):Chen, Xu(1); Fan, Wenhui(1,2,3)Source: Optics Letters Volume: 44 Issue: 23 DOI: 10.1364/OL.44.005876 Published: December 1, 2019Abstract:By arranging two pairs of high-index dielectric disks into a unit cell, a novel, to the best of our knowledge, terahertz metamaterials sensor integrated with a microfluidic channel is proposed. With the introduction of a new way of symmetry breaking in the unit cell, the strong toroidal dipole response with ultrahigh-Q is excited and investigated, which is related to the existence of the trapped mode. The simulation results show that the calculated quality factor and the corresponding figure of merit (FoM) of this sensor can reach 3189 and 515, respectively. These advantages allow for the proposed structure to have potential applications in high-performance gases, liquids, and biological materials sensing. ? 2019 Optical Society of America.Accession Number: 20194907777908 -
Record 18 of
Title:The near-space wind and temperature sensing interferometer: Forward model and measurement simulation
Author(s):He, Weiwei(1); Wu, Kuijun(2); Feng, Yutao(3); Fu, Di(3); Chen, Zhenwei(2); Li, Faquan(2)Source: Remote Sensing Volume: 11 Issue: 8 DOI: 10.3390/rs11080969 Published: April 1, 2019Abstract:Wind and temperature observation in near space has been playing an increasingly important role in atmospheric physics and space science. This paper reports on the near-space wind and temperature sensing interferometer (NWTSI), which employs a wide-angle Michelson interferometer to observe O2(a1Δg) dayglow near 1.27 μm from a limb-viewing satellite, and presents the instrument modeling and observation simulations from the stratosphere to the mesosphere and lower thermosphere. The characteristics of atmospheric limb-radiance spectra and line selection rules are described. The observational strategy of using two sets of three emission lines with a line-strength difference of one order of magnitude is proved to be suitable for extending altitude coverage. The forward modeling and measurement simulation of the expectedNWTSIobservations are provided, and the measurement uncertainty of the wind and temperature is discussed. The signal-to-noise ratio (SNR) and the limb-view weight work together to affect the precision of the wind and temperature measurements. The simulated results indicate a wind measurement precision of 1 to 3 m/s and a temperature precision of 1 to 3 K over an altitude range from 40 to 80 km, which meets the observing requirement in measurement precision for near-space detection. ? 2019 by the authors.Accession Number: 20191906870619 -
Record 19 of
Title:The radiative transfer characteristics of the O2 infrared atmospheric band in limb-viewing geometry
Author(s):He, Weiwei(1); Wu, Kuijun(2); Feng, Yutao(3); Fu, Di(3); Chen, Zhenwei(2); Li, Faquan(2)Source: Remote Sensing Volume: 11 Issue: 22 DOI: 10.3390/rs11222702 Published: November 1, 2019Abstract:The O2(a1Δg) emission near 1.27 μm provides an important means to remotely sense the thermal characteristics, dynamical features, and compositional structures of the upper atmosphere because of its photochemistry and spectroscopic properties. In this work, an emission-absorption transfer model for limb measurements was developed to calculate the radiation and scattering spectral brightness by means of a line-by-line approach. The nonlocal thermal equilibrium (non-LTE) model was taken into account for accurate calculation of the O2(a1Δg) emission by incorporating the latest rate constants and spectral parameters. The spherical adding and doubling methods were used in the multiple scattering model. Representative emission and absorption line shapes of the O2(a1Δg, v' = 0) → O2(X3Σg, v″= 0) band and their spectral behavior varying with altitude were examined. The effects of solar zenith angle, surface albedo, and aerosol loading on the line shapes were also studied. This paper emphasizes the advantage of using infrared atmospheric band for remote sensing of the atmosphere from 20 up to 120 km, a significant region where the strongest coupling between the lower and upper atmosphere occurs. ? 2019 by the authors.Accession Number: 20194807736445 -
Record 20 of
Title:Simulation of microchannel plate photomultiplier tube in high magnetic fields
Author(s):Chen, Ping(1,2,3,4); Yuan, Xiaohui(1,2); Tian, Jinshou(3,4); Wang, Xing(3); Wen, Wenlong(3); Guo, Lehui(3); Tian, Liping(3); Lu, Yu(3); Liu, Hulin(3); Wei, Yonglin(3); Pei, Chengquan(3); He, Kai(3); Sai, Xiaofeng(3); Wei, Wenqing(1,2); Deng, Yanqing(1,2); Zhao, Xu(1,2)Source: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 936 Issue: DOI: 10.1016/j.nima.2018.10.088 Published: 21 August 2019Abstract:The microchannel plate photomultiplier tube (MCP-PMT) used in high energy physics experiments usually needs to be able to operate in strong magnetic fields. In this paper, a 3D MCP-PMT model is developed in CST studio suite to study the magnetic field up to 5 T effect on the photoelectrons traveling from the photocathode to the MCP. Results predict that a growing number of photoelectrons strike back to the photocathode with enhancing magnetic field, which not only decreases electron collection efficiency and gain, but also impairs the photocathode lifetime. ? 2018 Elsevier B.V.Accession Number: 20190206350221 -
Record 21 of
Title:Mid-IR Faraday optical filter with an ultra-narrow single transmission peak at 5.33 μm
Author(s):Wu, Kuijun(1); Luo, Zhongjie(2); Feng, Yutao(3); Xiong, Yuanhui(1,2); Yu, Guangbao(1,2); Duan, Weimin(1); Li, Faquan(1)Source: Applied Physics Express Volume: 12 Issue: 9 DOI: 10.7567/1882-0786/ab3b3f Published: September 1, 2019Abstract:We present a theoretical and experimental study of a mid-infrared Faraday optical filter (MIFOF) with an ultra-narrow single transmission peak. The typical representative of paramagnetic molecules, gas-phase nitric oxide (NO), is selected as the working material. We focus on the transmission of such a filter operating on a Q(3/2) transition, and its dependence on the strength of the magnetic field. This MIFOF simultaneously achieves a peak transmission of 52%, an equivalent noise bandwidth (ENBW) of 444 MHz, and an out-of-band rejection ratio of 2 × 104, for a magnetic field of 17 mT and a NO pressure of 10 mbar. ? 2019 The Japan Society of Applied Physics.Accession Number: 20194107496570 -
Record 22 of
Title:An on-chip photon-pair source with negligible two-photon absoprtion
Author(s):Sugiura, Kenta(1); Okamoto, Ryo(1,2); Zhang, Labao(3); Kang, Lin(3); Chen, Jian(3); Wu, Peiheng(3); Chu, Sai T.(4); Little, Brent E.(5); Takeuchi, Shigeki(1)Source: Applied Physics Express Volume: 12 Issue: 2 DOI: 10.7567/1882-0786/aafa0f Published: February 2019Abstract:While photon-pair sources using silicon waveguides have shown great promise, strong two-photon absorption (TPA) may limit their brightness. Recently, high-index contrast doped glass (HICDG) has attracted attention because of its CMOS compatibility and low propagation loss. It is also expected that TPA in HICDG is small, though it has not yet been directly measured by conventionally used CW pumping. In this paper, we report that the estimated genuine coincidence events by photon-pairs increase quadratically as the pump power increased and do not show any saturation behavior up to 100 mW CW pump power. ? 2019 The Japan Society of Applied Physics.Accession Number: 20191006590142 -
Record 23 of
Title:A novel bowl-shaped microchannel plate with high electron collection efficiency and good time performance
Author(s):Chen, Ping(1,2,3,4); Tian, Jinshou(3,4); Yuan, Xiaohui(1,2); Wen, Wenlong(3); Wang, Xing(3); Guo, Lehui(3); Liu, Hulin(3); Wei, Yonglin(3); Pei, Chengquan(3); He, Kai(3); Lu, Yu(3); Sai, Xiaofeng(3); Wu, Wenqing(1,2); Deng, Yanqing(1,2); Zhao, Xu(1,2)Source: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 936 Issue: DOI: 10.1016/j.nima.2018.11.145 Published: 21 August 2019Abstract:Owing to the severe loss of photoelectrons striking at the input electrode of conventional microchannel plate (MCP), photoelectron collection efficiency (CE) of devices based on traditional MCP fluctuates around the MCP open area ratio and cannot make a breakthrough. Photoelectron backscattering from the MCP surface also causes late pulses smearing timing and spatial performance. In this work, a novel bowl-shaped MCP with an open area ratio higher than 90% whose input electrode is coated by a thin film with high secondary electron emission yield (SEY) is proposed as an effective approach to improve CE and suppress late pulses. A three-dimensional MCP-PMT model is developed in CST Studio Suite to evaluate CE and time performance of the bowl-shaped MCP, and compared with the traditional one. Results show that CE of the PMT based on the bowl-shaped MCP is nearly 100% and the delayed pulse is less than 2%. This indicates that good temporal and spatial resolution can be achieved with the bowl-shaped MCP. ? 2019 Elsevier B.V.Accession Number: 20190406423128 -
Record 24 of
Title:Flexible Affinity Matrix Learning for Unsupervised and Semisupervised Classification
Author(s):Fang, Xiaozhao(1); Han, Na(1); Wong, Wai Keung(2,3); Teng, Shaohua(1); Wu, Jigang(1); Xie, Shengli(4); Li, Xuelong(5,6)Source: IEEE Transactions on Neural Networks and Learning Systems Volume: 30 Issue: 4 DOI: 10.1109/TNNLS.2018.2861839 Published: April 2019Abstract:In this paper, we propose a unified model called flexible affinity matrix learning (FAML) for unsupervised and semisupervised classification by exploiting both the relationship among data and the clustering structure simultaneously. To capture the relationship among data, we exploit the self-expressiveness property of data to learn a structured matrix in which the structures are induced by different norms. A rank constraint is imposed on the Laplacian matrix of the desired affinity matrix, so that the connected components of data are exactly equal to the cluster number. Thus, the clustering structure is explicit in the learned affinity matrix. By making the estimated affinity matrix approximate the structured matrix during the learning procedure, FAML allows the affinity matrix itself to be adaptively adjusted such that the learned affinity matrix can well capture both the relationship among data and the clustering structure. Thus, FAML has the potential to perform better than other related methods. We derive optimization algorithms to solve the corresponding problems. Extensive unsupervised and semisupervised classification experiments on both synthetic data and real-world benchmark data sets show that the proposed FAML consistently outperforms the state-of-the-art methods. ? 2018 IEEE.Accession Number: 20183605782779