2017
2017
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Record 289 of
Title:Deconvolution of spectral power distribution of high-power laser diode arrays
Author(s):Zhang, Pu(1); Kim, Dae-Suk(2); Han, Bongtae(2)Source: Applied Optics Volume: 56 Issue: 20 DOI: 10.1364/AO.56.005590 Published: July 10, 2017Abstract:A novel method is proposed to predict the spectral power distributions (SPDs) of individual emitters in a highpower laser diode (LD) array. The proposed method deconvolutes the SPD of an LD array by taking into account the thermal cross-talk effect as well as the current competition effect. A complete analytical expression to deconvolute the SPD of an LD array is described. The expression contains four key parameters that are to be measured experimentally: (1) the normalized SPD of the central emitter, (2) the temperature coefficient of wavelength, (3) the current competition constant, and (4) the maximum power of the center emitter. The method is implemented with a commercial water-cooled high-power LD array. The SPD of the LD array predicted from the SPDs of individual emitters are compared with the experimentally measured SPD of the LD array. The results show excellent agreement in both shape and magnitude, which corroborates the validity of the proposed method. ? 2017 Optical Society of America.Accession Number: 20172903943120 -
Record 290 of
Title:Athermal design of refractive/diffractive hybrid infrared optical system
Author(s):Jiang, Yanru(1,2); Wang, Jing(1,2); Xie, Qingkun(1,2); Zhang, Wenfei(1,2); Qu, Enshi(1)Source: Optik Volume: 131 Issue: DOI: 10.1016/j.ijleo.2016.11.195 Published: February 1, 2017Abstract:Regarding the poor work conditions of military infrared optical instruments, there is usually a strong demand for athermalization and high resolution design. According to the properties of diffractive components in the optical passive athermalization, a diffractive-refractive hybrid infrared optical system working at 8 um–12 um is designed. It only contains four lenses with two aspheric and two diffractive surfaces, resulting in solutions with reducing overall size and weight, as well as enhancing performance characteristics. The MTF of this system demonstrates the optical system can realize athermalization over the temperature range from ?40 °C to 60 °C. In addition, the chromatic aberration and second spectrum are corrected simultaneously. ? 2016Accession Number: 20165003114668 -
Record 291 of
Title:Dwell time method based on Richardson-Lucy algorithm
Author(s):Jiang, Bo(1,2); Ma, Zhen(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10463 Issue: DOI: 10.1117/12.2285646 Published: 2017Abstract:When the noise in the surface error data given by the interferometer has no effect on the iterative convergence of the RL algorithm, the RL algorithm for deconvolution in image restoration can be applied to the CCOS model to solve the dwell time. By extending the initial error function on the edge and denoising the noise in the surface error data given by the interferometer, it makes the result more available. The simulation results show the final residual error 10.7912nm nm in PV and 0.4305 nm in RMS, when the initial surface error is 107.2414 nm in PV and 15.1331 nm in RMS. The convergence rates of the PV and RMS values can reach up to 89.9% and 96.0%, respectively. The algorithms can satisfy the requirement of fabrication very well. ? 2017 SPIE.Accession Number: 20180304654528 -
Record 292 of
Title:Double-beam fiber optical trap experiments based on supercontinuum laser
Author(s):Hu, Kong-Yun(1,2); Xiao, Guang-Zong(1,2); Zhang, Ying(1); Chen, Xin-Lin(1); Xie, Yuan-Ping(1)Source: Chinese Optics Volume: 10 Issue: 3 DOI: 10.3788/CO.20171003.0370 Published: June 1, 2017Abstract:The experimental system of dual-beam fiber optical trap is proposed and built for the first time which can realize the trapping and manipulation of polystyrene microspheres by taking the supercontinuum laser as the trapping light source. The position of the microsphere is manipulated by changing the relative position of the two optical fiber end faces and output power of the fibers. The CCD image analysis method is used to measure the position of the microsphere. The power spectrum is calculated by Fourier transform of the position variation of the confined Brown motion. After fitting the theoretical power spectrum function, the optical trap stiffness is obtained. The results show that when the power of the captured beam is 28 mW, the optical trap stiffness can reach 1.3×10-6 N/m, which is higher than that of the single wavelength optical trap under the same experimental conditions. By taking advantage of the wide spectrum of the dual-beam optical trap system, the physical parameters such as the size and refractive index can be obtained by studying the scattering spectrum information of the captured particles which is different from the traditional use of monochromatic light as the captured light of the optical tweezers. ? 2017, China Science Publishing & Media LTD. All right reserved.Accession Number: 20181905138956 -
Record 293 of
Title:Development and performance test of dynamic simulation system for X-ray pulsar navigation
Author(s):Xu, Neng(1,2,3); Sheng, Li-Zhi(1); Zhang, Da-Peng(4); Chen, Chen(1,2); Zhao, Bao-Sheng(1); Zheng, Wei(4); Liu, Chun-Liang(3)Source: Wuli Xuebao/Acta Physica Sinica Volume: 66 Issue: 5 DOI: 10.7498/aps.66.059701 Published: March 5, 2017Abstract:X-ray pulsar navigation is a complete autonomous navigation system, which has broad application prospects. Because of the huge cost of the navigation system, the implementation of ground simulation system is essential to the application of X-ray pulsar navigation. At present, most of researches on the semi physical experiment system are static. The aim of this article is to develop the dynamic simulation experiment system as well as its performance test. Specifically, this system consists of the dynamic signal database, X-ray simulation source, vacuum system and detection system designed for different science purposes. The core component of the X-ray source is the gate controlled X-ray tube, which can simulate the pulse profile of arbitrary waveform. The detecting system is based on the silicon drift detector with high time response capability. It uses trapezoidal shape for signal processing, and the timing resolution of the detection system is better than 2 μs. In addition, the dynamic signal generation method is given by analyzing the time transformation model while the SINC interpolation method is provided to generate the dynamic pulse profile. Finally, the spacecraft revolving around the earth for a circle and receiving a pulse signal of Crab is simulated. In the simulation, the orbital radius of satellite is 6578 km and the orbital period is 5400 s. The Crab pulsar is selected, and the pulse period is 33.4 ms, the number of photons received by the detector is 200 per second. As a contrast, a set of static experiments is also performed. The correlation coefficient between the cumulative pulse profile and the standard pulse profile is 0.9953. However, the correlation coefficient decreases gradually, from 0.9094 at 300 s to 0.4080 at 5400 s, in the dynamic experiment. Then, the pulse period is searched from the arrival time of photons. The periodicity of the pulse signal is sinusoidal when the search period is 60 s. The change rate of photon flux is less than 2%, and the influence on the period search is negligible. The variation of pulse period is consistent with the motion law of spacecraft, which indicates that spacecraft motion is the dominant factor in time conversion. Finally, the arrival time of photons is transformed into the time at the solar system barycenter, indicating that the correlation coefficient between cumulative pulse profile and standard pulse profile is 0.9882. The result shows that the simulation system can simulate the X-ray pulse signal received by the spacecraft in orbit, which can provide the experimental basis for verifying the navigation algorithm and calibrating the detector performance. ? 2017 Chinese Physical Society.Accession Number: 20171803621502 -
Record 294 of
Title:Noninvasive blood glucose detection using a miniature wearable Raman spectroscopy system
Author(s):Zheng, Yi(1,2); Zhu, Xiangping(1); Wang, Zhe(3); Hou, Zongyu(3); Gao, Fei(1); Nie, Rongzhi(1,4); Cui, Xiaoxia(1); She, Jiangbo(1); Peng, Bo(1)Source: Chinese Optics Letters Volume: 15 Issue: 8 DOI: 10.3788/COL201715.083001 Published: August 10, 2017Abstract:In this Letter, a miniature wearable Raman spectroscopy system is developed. A wearable fiber-optic probe is employed to help the stable and convenient collection of Raman spectra. A nonlinear partial least squares model based on a multivariate dominant factor is employed to predict the glucose level. The mean coefficients of determination are 0.99, 0.893, and 0.844 for the glucose solution, laboratory rats, and human volunteers. The results demonstrate that a miniature wearable Raman spectroscopy system is feasible to achieve the noninvasive detection of human blood glucose and has important clinical application value in disease diagnosis. ? 2017 Chinese Optics Letters.Accession Number: 20174604403969 -
Record 295 of
Title:Re-weighted discriminatively embedded K-means for multi-view clustering
Author(s):Xu, Jinglin(1); Han, Junwei(1); Nie, Feiping(2); Li, Xuelong(3)Source: IEEE Transactions on Image Processing Volume: 26 Issue: 6 DOI: 10.1109/TIP.2017.2665976 Published: June 2017Abstract:Recent years, more and more multi-view data are widely used in many real-world applications. This kind of data (such as image data) is high dimensional and obtained from different feature extractors, which represents distinct perspectives of the data. How to cluster such data efficiently is a challenge. In this paper, we propose a novel multi-view clustering framework, called re-weighted discriminatively embedded K -means, for this task. The proposed method is a multi-view least-absolute residual model, which induces robustness to efficiently mitigates the influence of outliers and realizes dimension reduction during multi-view clustering. Specifically, the proposed model is an unsupervised optimization scheme, which utilizes iterative re-weighted least squares to solve least-absolute residual and adaptively controls the distribution of multiple weights in a re-weighted manner only based on its own low-dimensional subspaces and a common clustering indicator matrix. Furthermore, theoretical analysis (including optimality and convergence analysis) and the optimization algorithm are also presented. Compared with several state-of-the-art multi-view clustering methods, the proposed method substantially improves the accuracy of the clustering results on widely used benchmark data sets, which demonstrates the superiority of the proposed work. ? 1992-2012 IEEE.Accession Number: 20172003669299 -
Record 296 of
Title:Effects of doping SiO2 on the defect's change in B2O3-containing phosphate based laser glasses used for high energy UV lasers
Author(s):Sun, Mengya(1,2); Duan, Zhanjun(3); Wang, Pengfei(1); Lu, Min(1); Peng, Bo(1)Source: Optical Materials Express Volume: 7 Issue: 11 DOI: 10.1364/OME.7.004111 Published: 2017Abstract:The introduction of SiO2 affects the glass's micro-structure and micro-defects as well as the corresponding optical and physical properties of the B2O3-containing multicomponent phosphate glasses. The addition of SiO2 increases the transition temperature and causes shifts of the UV cut-offwavelength (λcut-off). The changes of λcut-offare closely related to the PO3-EC and PO4-EC defect centers that are associated with the Q2 tetrahedral in phosphate chains. The corresponding variations of Q2 units can also be found in the Raman, XPS, and 31P MAS-NMR spectra. With increasing the content of SiO2, the ratio of nonbridging oxygen (associated with Q2 units) is gradually decreased down to a critical level when SiO2/B2O3 ratio is 4/1.5, whereas the ratio of non-bridging oxygen increases when SiO2/B2O3 ratio is larger than 4/1.5, which suggests that the doping SiO2 can influence the concentration of PO3-EC and PO4-EC defects. Those results can be better obtained when the sample is exposed to gamma irradiation. As the SiO2 content increased gradually up to 4/1.5, the concentration of the PO3-EC defects declined, while the concentration of PO4-EC and the POHC defects increased when considering the irradiation dose, indicating that the addition of SiO2 can regulate the structure-related defects in phosphate based glasses. ? 2017 Optical Society of America.Accession Number: 20174404315730 -
Record 297 of
Title:Fabrication of micro hole array on the surface of CVD ZnS by scanning ultrafast pulse laser for antireflection
Author(s):Li, Yangping(1); Zhang, Tianhui(1); Fan, Siling(1); Cheng, Guanghua(2)Source: Optical Materials Volume: 66 Issue: DOI: 10.1016/j.optmat.2017.02.019 Published: April 1, 2017Abstract:Chemical vapor deposited (CVD) ZnS is a promising long-wave infrared (8–12 μm) window material. Yet antireflection is necessary since Fresnel reflection from its surface is high due to the high refractive index of ZnS. Sub-wavelength structured surface of micro hole array was fabricated on CVD ZnS by scanning ultrafast pulse laser ablation. The effects of beam profile, pulse width and beam power on the radius and morphology of the holes were studied. Gaussian beam can cause severe melted-resolidified layers around the hole, yet Bessel beam only resulted in thin ribbon around the hole. The picosecond Bessel laser is more suitable than femtosecond laser for ablating holes on ZnS. The radius of the holes increases with increasing the Bessel beam pulse width and the beam power. But larger power may cause circle grooves around the central holes. Ordered hole array was fabricated on single side of CVD ZnS and antireflection was realized. ? 2017 Elsevier B.V.Accession Number: 20170903396367 -
Record 298 of
Title:Non-diffracting optical Bloch oscillations in hexagonal photonic lattices
Author(s):Liu, Sheng(1); Rao, Bingjie(1); Wang, Meirong(1); Zhang, Peng(2); Xiao, Fajun(1); Gan, Xuetao(1); Zhao, Jianlin(1)Source: Optics Express Volume: 25 Issue: 7 DOI: 10.1364/OE.25.007475 Published: April 3, 2017Abstract:Light beams undergoing optical Bloch oscillations (OBOs) in two-dimensional (2D) photonic lattices suffer from severe diffraction along the perpendicular direction to the oscillation plane. In this paper, we propose and demonstrate that such diffraction could be suppressed in hexagonal photonic lattices via sophisticated managements of the discrete diffraction. By positioning the Fourier spectrum of the beam to a special region in the Brillouin zone, the light driven by the OBO experiences normal and anomalous diffractions alternatively, leading to a non-diffracting propagation for a long distance. We show that non-diffracting OBOs can be implemented not only for Gaussian beam but also for other complex 2D beams including self-accelerating Airy beams and vortex beams. Our results provide novel insights into the diffraction or dispersion engineering of waves in periodic structures. ? 2017 Optical Society of America.Accession Number: 20171403544917 -
Record 299 of
Title:Study of Ultraviolet Photon Counting Detector with Delay-Line Anode
Author(s):Lei, Fan-Pu(1,2,3); Bai, Yong-Lin(3); Zhu, Bing-Li(3); Bai, Xiao-Hong(3); Qin, Jun-Jun(3); Xu, Peng(3); Hou, Xun(1)Source: Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis Volume: 37 Issue: 10 DOI: 10.3964/j.issn.1000-0593(2017)10-2989-06 Published: October 1, 2017Abstract:Delay-line anode detector based on MCP electron multiplier detect the incident photon's location by the arrival time difference of the MCP output charge pulse at each end of delay line. Due to their high spatial resolution and high counting rate, photon counting detectors with delay line anode have been widely used in ultraviolet spectral imaging systems. Operational principle of ultraviolet photon detector based on delay line anode is analyzed, and a novel two-dimensional serpentine delay line anode is designed. Electron cloud output from MCP is collected only by the anode surface. The upper serpentine delay line receives the MCP output charge directly, while the lower serpentine delay line receives the charge using a series of pads and vias. This anode is made of printed circuit board instead of laser etching, which greatly simplifies the fabrication process. Photon counting detector with this type of anode achieves a 92 μm FWHM resolution. And the image linearity is better than 100 μm. The results of theory analysis and experiments demonstrated the feasibility of ultraviolet photon imaging system. It provides a theoretical basis and experiments guidance for the development of ultraviolet imaging spectrometers. ? 2017, Peking University Press. All right reserved.Accession Number: 20181004855777 -
Record 300 of
Title:Double line and tubular depressed cladding waveguides written by femtosecond laser irradiation in PTR glass
Author(s):Zhang, Y.J.(1,2); Zhang, G.D.(2); Bai, J.(2); Chen, C.L.(1); Stoian, R.(3); Cheng, G.H.(2)Source: Optical Materials Express Volume: 7 Issue: 7 DOI: 10.1364/OME.7.002626 Published: 2017Abstract:Depressed cladding concepts such as double line depressed index and tubular low index cladding waveguide structures were fabricated in bulk photo-thermo-refractive glass using femtosecond laser pulses. Effects of the writing laser power, waveguide geometrical structures and heat treatment on the light guiding properties were investigated. The results show that depressed cladding tubular waveguide design exhibits better guiding performances than double line waveguides in PTR glass. For the tubular cladding waveguide, single and multimode fields can be obtained for a wide processing parameter window. The simulations agree well with the experiment results. Moreover, the normalized frequency can be tuned and the quality of the depressed cladding tubular waveguide can be improved by eliminating uneven stress distribution after heat treatment. ? 2017 Optical Society of America.Accession Number: 20172703888612