2017
2017
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Record 25 of
Title:In situ measurement of the topological charge of a perfect vortex using the phase shift method
Author(s):Ma, Haixiang(1); Li, Xinzhong(1,2); Tai, Yuping(3); Li, Hehe(1); Wang, Jingge(1); Tang, Miaomiao(1); Wang, Yishan(2); Tang, Jie(2); Nie, Zhaogang(4)Source: Optics Letters Volume: 42 Issue: 1 DOI: 10.1364/OL.42.000135 Published: January 1, 2017Abstract:We propose a method to determine the topological charge (TC) of a perfect vortex. With the phase shift technique, the perfect vortex and its conjugate beam exactly overlap and interfere. Consequently, the TC of a perfect vortex is determined by counting the number of interference fringes. This proposed method enables in situ determination of the TC of the perfect vortex without the need for additional optical elements, and it is immune to environmental vibration and parasitic interference. ? 2016 Optical Society of America.Accession Number: 20170403269492 -
Record 26 of
Title:Generation of Circular Optical Vortex Array
Author(s):Ma, Haixiang(1); Li, Xinzhong(1,2); Tai, Yuping(3); Li, Hehe(1); Wang, Jingge(1); Tang, Miaomiao(1); Tang, Jie(2); Wang, Yishan(2); Nie, Zhaogang(4)Source: Annalen der Physik Volume: 529 Issue: 12 DOI: 10.1002/andp.201700285 Published: December 2017Abstract:We report on a novel optical vortex array named circular optical vortex array, which is generated by the superposition of two concentric perfect optical vortices. The circular optical vortex array has a constant topological charge of +1 or ?1, the number and sign of which are determined by the topological charges of the two perfect optical vortices. Moreover, the radius of the circular optical vortex array is easily adjusted by using the cone angle of an axicon. Furthermore, the circular optical vortex array and multiple circular optical vortex array can be rotated by changing the initial phase difference of the perfect optical vortices on demand. This work demonstrates a complex structured optical field, which is of significance for applications such as optical tweezers, micro-particle manipulation, and optical imaging. ? 2017 by WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimAccession Number: 20175004516606 -
Record 27 of
Title:Reconfigurable broadband microwave photonic intensity differentiator based on an integrated optical frequency comb source
Author(s):Xu, Xingyuan(1); Wu, Jiayang(1); Shoeiby, Mehrdad(2); 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: APL Photonics Volume: 2 Issue: 9 DOI: 10.1063/1.4989871 Published: September 1, 2017Abstract:We propose and experimentally demonstrate a microwave photonic intensity differentiator based on a Kerr optical comb generated by a compact integrated micro-ring resonator (MRR). The on-chip Kerr optical comb, containing a large number of comb lines, serves as a high-performance multi-wavelength source for implementing a transversal filter, which will greatly reduce the cost, size, and complexity of the system. Moreover, owing to the compactness of the integrated MRR, frequency spacings of up to 200-GHz can be achieved, enabling a potential operation bandwidth of over 100 GHz. By programming and shaping individual comb lines according to calculated tap weights, a reconfigurable intensity differentiator with variable differentiation orders can be realized. The operation principle is theoretically analyzed, and experimental demonstrations of the first-, second-, and third-order differentiation functions based on this principle are presented. The radio frequency amplitude and phase responses of multi-order intensity differentiations are characterized, and system demonstrations of real-time differentiations for a Gaussian input signal are also performed. The experimental results show good agreement with theory, confirming the effectiveness of our approach. ? 2017 Author(s).Accession Number: 20173904217981 -
Record 28 of
Title:Optical system design of compound multi-point measurement velocity interferometer
Author(s):Yan, Ya-Dong(1); He, Jun-Hua(1); Xu, Rui-Hua(1); Wei, Ming-Zhi(1); Li, Qi(1)Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 25 Issue: 8 DOI: 10.3788/OPE.20172508.2023 Published: August 1, 2017Abstract:In order to measure velocities of explosion loading surface driven by blast waves, a compound velocity interferometer was introduced. The illumination laser from fiber array was projected onto the target surface through a telecentric optical imaging system. Only several points on the target were illuminated, which got the utmost out of laser power. The illumination beam had so small numerical aperture that the illumination spot size kept constant while the target moving within 10 mm. A taper fiber array with large core diameter was mounted on the image surface of optical imaging system, thus the signals could coupled into the large core fibers effectively and could output in single mode for difference interference in single mode Mach-Zender interferometer during the target movement. A 45° beam splitter with a small wedge angle was employed before the first optical element of the imaging system, the illumination laser could be reflected to the object surface by the rectangular films on the first surface of the splitter. The small wedge angle of the splitter could compensate the astigmatism lead by titled parallel plate. During the object surface moving within 10 mm, the lighting power and spot sizes on object surface remain the same, and the coupling efficiency of Doppler frequency shift signals also remain constant. This optical system could meet the demand of explosion loading surface velocity measurement in long distance range. ? 2017, Science Press. All right reserved.Accession Number: 20174204280435 -
Record 29 of
Title:Generation of complex quantum states via integrated frequency combs
Author(s):Reimer, Christian(1); Kues, Michael(1,2); Roztocki, Piotr(1); Wetzel, Benjamin(1,3); Little, Brent E.(4); Chu, Sai T.(5); Caspani, Lucia(6); Moss, David J.(7); Morandotti, Roberto(1,8)Source: Proceedings of the 2017 Design, Automation and Test in Europe, DATE 2017 Volume: Issue: DOI: 10.23919/DATE.2017.7927012 Published: May 11, 2017Abstract:The generation of optical quantum states on an integrated platform will enable low cost and accessible advances for quantum technologies such as secure communications and quantum computation. We demonstrate that integrated quantum frequency combs (based on high-Q microring resonators made from a CMOS-compatible, high refractive-index glass platform) can enable, among others, the generation of heralded single photons, cross-polarized photon pairs, as well as bi- and multi-photon entangled qubit states over a broad frequency comb covering the S, C, L telecommunications band, constituting an important cornerstone for future practical implementations of photonic quantum information processing. ? 2017 IEEE.Accession Number: 20172303739792 -
Record 30 of
Title:Modeling and control of Takagi-Sugeno fuzzy hyperbolic model for a class of nonlinear systems
Author(s):Li, Junmin(1); Wang, Jiaxian(1); Chen, Minglai(1,2)Source: Journal of Intelligent and Fuzzy Systems Volume: 33 Issue: 6 DOI: 10.3233/JIFS-161780 Published: 2017Abstract:In this paper, a Takagi-Sugeno (T-S) fuzzy hyperbolic model is proposed for the fuzzy control of a class of nonlinear systems. The consequence of the proposed model is a hyperbolic tangent dynamic model, and it is employed to represent the nonlinear system. By constructing a new Lyapunov function, the stability conditions of the open-loop T-S fuzzy hyperbolic system are derived via linear matrix inequalities (LMIs). Then, the parallel distributed compensation (PDC) method is used to design a fuzzy hyperbolic controller, and the asymptotic stability conditions of the closed-loop system are formulated via LMIs. The main advantage of the control based on T-S fuzzy hyperbolic model is that it can achieve small control amplitude via "soft" constraint control approach. Finally, the effectiveness and advantage of the proposed schemes are illustrated by a mathematical constructive example and the Van de Vusse example. ? 2017 - IOS Press and the authors. All rights reserved.Accession Number: 20174904512610 -
Record 31 of
Title:The simulation and experiment of a time-resolved polarization interferometer
Author(s):Gao, Xiaohui(1); Yu, Tao(1); Wu, Yinhua(1); Wei, Ruyi(1); Xu, Guanghui(2)Source: Proceedings - 2017 10th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics, CISP-BMEI 2017 Volume: 2018-January Issue: DOI: 10.1109/CISP-BMEI.2017.8302038 Published: July 2, 2017Abstract:In a traditional dual optics routes Michelson interferometer, the critical time delay is acquired by scanning one mirror that needs a precision physical translation mechanism. The so-called translation mechanism usually dominates the risk, cost, power consumption, and performance of such instruments which limits the development of interference spectrometer. This paper describes the principle of a novel temporal modulated interference spectrometer that generates time delay by using birefringence crystal because of speed difference and the refraction indexes between the ordinary and the extraordinary component. A greater optical path difference can be abstained by cascading a series of wave plates that interlaced with a series of achromatic ferroelectric liquid crystal switches. Through the simulation analysis and experiment of the principle of polarization interference spectrometer, it demonstrates the validity of the instrument principle and data inversion method. ? 2017 IEEE.Accession Number: 20182205255953 -
Record 32 of
Title:Hardware design of video compression system based on TMS320DM368
Author(s):He, Bian(1); Lei, Yang(1); Jiawen, Liao(1); Jia, Feng(1); Hao, Wang(1); Hua, Wang(1)Source: Proceedings - 9th International Conference on Intelligent Human-Machine Systems and Cybernetics, IHMSC 2017 Volume: 2 Issue: DOI: 10.1109/IHMSC.2017.178 Published: September 20, 2017Abstract:HD video data is visible in the real-Time compression processing is one of the key technologies, The current video compression codec hardware platform mainly includes: ASIC, DSP and SoC. These three kinds of SOC chips have become the mainstream of the codec chip market because of their low cost, low power consumption and high integration. According to Da Vinci of TI processor TMS320DM368 as the core architecture, The hardware system of high definition video compression processing based on embedded technology is designed, which includes video input ISIF interface module, communication module, core processor module, peripheral circuit module and power module. This system supports 1080P30 HD video capture hardware frame, H.264 encoding compression and local storage, can be widely used in industrial control, medical, aerospace and other industries, has important application value in engineering. ? 2017 IEEE.Accession Number: 20174704432668 -
Record 33 of
Title:Design of a smooth freeform illumination system for a point light source based on polar-type optimal transport mapping
Author(s):Mao, Xianglong(1); Xu, Songbo(1); Hu, Xinrong(1); Xie, Yongjun(1)Source: Applied Optics Volume: 56 Issue: 22 DOI: 10.1364/AO.56.006324 Published: August 1, 2017Abstract:A design method is proposed to generate smooth freeform illumination optics for a point light source based on the L2 optimal transport (LOT) mapping. In this method, the LOT mapping between an assumed circular planar source and a prescribed target is first obtained by solving a polar-type LOT problem. Then, the mapping calculated for the circular source is applied for a point light source. Finally, the freeform optical surface is generated by a geometric construction method to realize the ray mapping. As examples, a series of smooth-surface freeform lenses are designed for a point light source to form uniform and complex illumination patterns on rectangular targets. The ray-tracing results show that all the designs achieve excellent performance with the light utilization efficiency η over 0.87 (Fresnel loss considered) and the relative standard deviation (RSD) of the simulated illumination distribution less than 0.051 simultaneously. ? 2017 Optical Society of America.Accession Number: 20173104014165 -
Record 34 of
Title:Design of multichannel data acquisition system based on Ethernet
Author(s):He, Bian(1); Guangsen, Liu(1); Huawei, Wang(1); Jia, Feng(1); Bo, Gao(1); Hongtao, Yang(1)Source: International Conference on Communication Technology Proceedings, ICCT Volume: 2017-October Issue: DOI: 10.1109/ICCT.2017.8359725 Published: July 2, 2017Abstract:In order to multi-channel image data can be collected at the same time, Data package, Sent to the host computer, a multi-channel data acquisition scheme based on Ethernet transmission is proposed. Using synchronous RS422 bus + FPGA + Gigabit Ethernet hardware platform and multi-channel image data loop acquisition algorithm to achieve multi-channel image data through the synchronous RS422 bus into the FPGA, time-sharing by the FPGA for each road data collection, and then Gigabit Ethernet Network sent to the host computer. In the FPGA, the MAC address, IP address, UDP header and channel number are added to each image data, and the multi-channel data collection algorithm is adopted to overcome the phenomena of image data loss and channel disorder. 8 camera modules as a data source for testing, the results show that each road image data is completely correct to the host computer for display, image data packet loss rate of 0%, repeat rate of 0%, to meet the expected requirements, to achieve the purpose of detection of multi-channel transmission of data. ? 2017 IEEE.Accession Number: 20182305271222 -
Record 35 of
Title:Realization on image 2D-DCT sparse transform based on FPGA
Author(s):Zhang, Haifeng(1)Source: 2016 13th International Computer Conference on Wavelet Active Media Technology and Information Processing, ICCWAMTIP 2017 Volume: 2018-February Issue: DOI: 10.1109/ICCWAMTIP.2017.8301473 Published: July 2, 2017Abstract:Sampling is a necessary course that the Analog physical world leads to the world of digital information. Compressed sensing (CS) theory breaks through the traditional Nyquist sampling theorem for data acquisition. The research object of CS theory is a sparse representation of signals and here 2-D image sparse transform is achieved based on discrete cosine orthogonal basis. Furthermore, there are a presentation of 2D-DCT algorithm based on row-column decomposition structure and an illustration of the optimization algorithm of 1-D DCT based on FPGA emphatically, as well as the transpose RAM method between two levels 1-D DCT. Finally the rationality of the proposed algorithm is verified by comparing image 2D-DCT transformation based on FPGA and 2D-DCT calculation result in MATLAB. ? 2017 IEEE.Accession Number: 20183105636310 -
Record 36 of
Title:Practical system for the generation of pulsed quantum frequency combs
Author(s):Roztocki, Piotr(1); Kues, Michael(1,2); Reimer, Christian(1); Wetzel, Benjamin(1,3); Sciara, Stefania(1,4); Zhang, Yanbing(1); Cino, Alfonso(4); Little, Brent E.(5); Chu, Sai T.(6); Moss, David J.(7); Morandotti, Roberto(1,8,9)Source: Optics Express Volume: 25 Issue: 16 DOI: 10.1364/OE.25.018940 Published: August 7, 2017Abstract:The on-chip generation of large and complex optical quantum states will enable low-cost and accessible advances for quantum technologies, such as secure communications and quantum computation. Integrated frequency combs are on-chip light sources with a broad spectrum of evenly-spaced frequency modes, commonly generated by four-wave mixing in optically-excited nonlinear micro-cavities, whose recent use for quantum state generation has provided a solution for scalable and multi-mode quantum light sources. Pulsed quantum frequency combs are of particular interest, since they allow the generation of single-frequency-mode photons, required for scaling state complexity towards, e.g., multi-photon states, and for quantum information applications. However, generation schemes for such pulsed combs have, to date, relied on micro-cavity excitation via lasers external to the sources, being neither versatile nor power-efficient, and impractical for scalable realizations of quantum technologies. Here, we introduce an actively-modulated, nested-cavity configuration that exploits the resonance pass-band characteristic of the micro-cavity to enable a mode-locked and energy-efficient excitation. We demonstrate that the scheme allows the generation of high-purity photons at large coincidence-to-accidental ratios (CAR). Furthermore, by increasing the repetition rate of the excitation field via harmonic mode-locking (i.e. driving the cavity modulation at harmonics of the fundamental repetition rate), we managed to increase the pair production rates (i.e. source efficiency), while maintaining a high CAR and photon purity. Our approach represents a significant step towards the realization of fully on-chip, stable, and versatile sources of pulsed quantum frequency combs, crucial for the development of accessible quantum technologies. ? 2017 Optical Society of America.Accession Number: 20173204034220