2013
2013
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Record 481 of
Title:A stable polarization-insensitive wavelength converter based on nonlinear wave mixing in PCF
Author(s):Xie, Xiaoping(1); Huang, Xinning(1)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: Published: 2013Abstract:A stable wavelength converter is experimentally demonstrated in this work, which can realize polarization-insensitive wavelength switching with polarizat ion dependence-9 BER level. The converted output signal OSNR is better than 30dB. ? OSA 2013.Accession Number: 20141617577119 -
Record 482 of
Title:Influence of driving frequency on discharge modes in a dielectric-barrier discharge with multiple current pulses
Author(s):Jiang, Weiman(1); Tang, Jie(1); Wang, Yishan(1); Zhao, Wei(1); Duan, Yixiang(1,2)Source: Physics of Plasmas Volume: 20 Issue: 7 DOI: 10.1063/1.4817289 Published: July 2013Abstract:A one-dimensional self-consistent fluid model was employed to investigate the effect of the driving frequency on the discharge modes in atmospheric-pressure argon discharge with multiple current pulses. The discharge mode was discussed in detail not only at current peaks but also between two adjacent peaks. The simulation results show that different transitions between the Townsend and glow modes during the discharge take place with the driving frequency increased. A complicated transition from the Townsend mode, through glow, Townsend, and glow, and finally back to the Townsend one is found in the discharge with the driving frequency of 8 kHz. There is a tendency of transition from the Townsend to glow mode for the discharge both at the current peaks and troughs with the increasing frequency. The discharge in the half period can all along operate in the glow mode with the driving frequency high enough. This is resulted from the preservation of more electrons in the gas gap and acquisition of more electron energy from the swiftly varying electric field with the increase in driving frequency. Comparison of the spatial and temporal evolutions of the electron density at different driving frequencies indicates that the increment of the driving frequency allows the plasma chemistry to be enhanced. This electrical characteristic is important for the applications, such as surface treatment and biomedical sterilization. ? 2013 AIP Publishing LLC.Accession Number: 20133416653680 -
Record 483 of
Title:Development of a diffuse air-argon plasma source using a dielectric-barrier discharge at atmospheric pressure
Author(s):Tang, Jie(1); Jiang, Weiman(1); Zhao, Wei(1); Wang, Yishan(1); Li, Shibo(1); Wang, Haojing(1); Duan, Yixiang(1,2)Source: Applied Physics Letters Volume: 102 Issue: 3 DOI: 10.1063/1.4788721 Published: January 21, 2013Abstract:A stable diffuse large-volume air plasma source was developed by using argon-induced dielectric-barrier discharges at atmospheric pressure. This plasma source can be operated in a filamentary discharge with the average areal power density of 0. 27 W / cm2 and the gas temperature of 315 ± 3 K. Spatial measurement of emission spectrum and temperature indicates that this plasma is uniform in the central region along the transverse direction. It is also found that the formation of diffuse air plasma mainly lies in the creation of sufficient seed electrons by the Penning effect through collisions between two argon or nitrogen metastables at low electric fields. ? 2013 American Institute of Physics.Accession Number: 20130515972065 -
Record 484 of
Title:The influence of atmospheric turbulence on IM/DD space optical communication system
Author(s):Wei, Anhai(1,2); Han, Biao(1); Zhao, Wei(1); Xie, Xiaoping(1); Hu, Hui(1,2); Su, Yulong(1,2); Zhang, Kewei(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8906 Issue: DOI: 10.1117/12.2033028 Published: 2013Abstract:Lots of researches have simulated performance of optical system based on plane wave or spherical wave model, but optical field is Gauss distribution in real optical communication system. So we derive the relationships between the signal-to-noise ratio (SNR), bit error rate (BER), channel capacity (C) and the transmission distance of the space laser communication system, which is obtained by the Gaussian beam propagation model for on-off keying (OOK) modulated signal under horizontal link. We numerically study the influence of atmospheric turbulence on system performance. we get the conclusions: Under weak turbulence intensity, as the turbulence intensity increases, the C and SNR for OOK modulated space laser communication system decrease while the BER increase; In the case of strong turbulence intensity, the intensity scintillation and the BER dramatically increase with the increase of transmission distance, and then become saturated; In the condition of turbulence intensity and transmission distance are both constant, the longer the wavelength results in greater C, higher SNR and lower BER. Selecting longer communication wavelength can mitigate the impact of the atmosphere turbulence on the communication system in some extent. ? 2013 Copyright SPIE.Accession Number: 20141317501146 -
Record 485 of
Title:Arbitrary waveform generator based on GaAS FET and tapered micro-strip line
Author(s):Lin, Ping(1,2); Liu, Baiyu(1); Gou, Yongsheng(1); Bai, Yonglin(1); Wang, Bo(1); Zhao, Xueqing(3)Source: Advanced Materials Research Volume: 655-657 Issue: DOI: 10.4028/www.scientific.net/AMR.655-657.1581 Published: 2013Abstract:In order to improve the output power of laser pulse in the inertia confinement fusion experiment, an arbitrary waveform generator is fabricated to shape the laser pulse. The arbitrary waveform generator is based on the impedance tapered micro-strip line technology and GaAs Field Effect Transistor set which has a good ability of generating voltage-controlled current. With the impedance tapered micro-strip line technology, the arbitrary waveform generator generates shaping electrical pulse with duration less than 10 ns, 330 ps time-domain adjustment. We use the shaping electrical pulse to modulate semiconductor laser which has the characteristic of direct modulate, the experiment results show the shaped laser pulse is obtained based on the shaping electrical pulse. ? (2013) Trans Tech Publications, Switzerland.Accession Number: 20130916062121 -
Record 486 of
Title:Research on the method of fast photoelectric diagnostics based on ordinary CCD
Author(s):Zhu, Bingli(1); Bai, Yonglin(1); Liu, Baiyu(2); Wang, Bo(2); Bai, Xiaohong(2); Gou, Yongsheng(1); Qin, Junjun(2); Yang, Wenzheng(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8908 Issue: DOI: 10.1117/12.2032841 Published: 2013Abstract:A novel method to realize fast photoelectric diagnostics using ordinary CCD is presented. By changing the mode of charge transfer of CCD, fast photoelectric diagnostics of single point with linear CCD and high-speed line scanning with array CCD can be achieved respectively. A fast photoelectric diagnostics system of single point based on linear CCD has been designed and fabricated to investigate the feasibility of this method. A pulsed blue light emitting diode (LED) has been used to measure the system. As a proof of concept, the rate of photoelectric diagnostics of single point reachs up to 20 MHz. The results demonstrated that the method of fast photoelectric diagnostics based on ordinary CCD is feasible. ? 2013 SPIE.Accession Number: 20134216857653 -
Record 487 of
Title:Femtosecond laser multi-beam interference lithography anti-reflective microstructure on silicon surface
Author(s):He, Feng-Tao(1); Zhou, Qiang(1,2); Yang, Wen-Zheng(3); Long, Xue-Wen(2); Bai, Jing(2); Cheng, Guang-Hua(2)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 42 Issue: 5 DOI: 10.3788/gzxb20134205.0515 Published: May 2013Abstract:In order to obtain uniform distribution silicon surface microstructure, a new method was proposed based on multi-beam interference lithography to relaise the controlling of the distribution character of the microstructure. Femtosecond laser multi-beam interference was formed by Spatial Light Modulator (SLM), and the uniform distribution multi-spots with the controllable period were generated. By using these multi-spots, the regular distribution concave structures were fabricated on silicon surface, and the distribution character and period was flexiblly controlled by shift the phase masks on SLM. The morphology and optical character of the microstructure were measured with Scanning Electron Microscopy (SEM) and spectrophotometer. Experimental results show that the close-packed concave structure with the period of about 3.3 μm can be fabricated on the silicon surface under special parameters (10× focusing lens, laser power of 25 mW, exposing time of 30 s) by loading the phase of 4-facet pyramid lens with the base angle of 2°; the formed structure shows good effect of anti-reflection; its transmission at the near infrared band of 1.2~2 μm enhances 11.5% in comparison with the polished silicon.Accession Number: 20132516429278 -
Record 488 of
Title:Theoretical and experimental study on methods for increasing squeezed level in the generation of squeezed light
Author(s):Feng, Fei(1,2); Qu, Wen-Yan(1,2); Song, Jia-Zheng(1); Zhang, Tong-Yi(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8906 Issue: DOI: 10.1117/12.2034574 Published: 2013Abstract:We demonstrate the methods for increasing the observed squeezing level in the generation of squeezed states of light at 1064 nm with periodically poled KTiOPO4 (PPKTP) crystal. We analyze the technical limits to the reduction of noise in the squeezed quadrature theoretically, including the intra-cavity loss of the optical parametric amplifier (OPA) cavity, the normalized amplitude, the detection frequency, and the mode matching on the balanced homodyning stage. To observe a high degree of squeezing, we improve the quality of mode matching into the OPA cavity and the mode cleaning (MC) cavity experimentally. By optimizing mode matching of the light into cavities, the finesse of the cavities would be higher in practice and the desirable spatial mode can be realized. As the intensity noise of the laser light reach the shot noise limit above the frequency of 1 MHz, which is sufficient for our experiment, so the MC cavity is incorporated to filter higher-order transverse modes of the local oscillator (LO) beam for the balanced homodyne detection. The experimental and theoretical results show that it is essential to optimize the mode matching efficiency to generate and detect high degree of squeezing otherwise an inefficiency mode matching will throw away the squeezing and transform the squeezed field into a vacuum field. ? 2013 Copyright SPIE.Accession Number: 20141317501178