The Experts below are selected from a list of 39291 Experts worldwide ranked by ideXlab platform
Ting Wang - One of the best experts on this subject based on the ideXlab platform.
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polarization multiplexed optical wireless transmission with Coherent Detection
Journal of Lightwave Technology, 2010Co-Authors: Neda Cvijetic, Dayou Qian, Yuekai Huang, Ting WangAbstract:In this paper, we propose, analyze, and experimentally verify polarization-multiplexed optical wireless transmission with Coherent Detection as a means of improving performance and increasing the per-wavelength data rate in the presence of atmospheric turbulence. It is first shown that in terrestrial last-mile applications, the polarization state changes of the optical wireless signal are governed by optical source properties both in the absence and in the presence of mild to moderately severe turbulence. Under these conditions, it is shown that the polarization evolution is reduced to a polarization state rotation wherein the cross-polarization interference can be equalized with well-known blind algorithms. We also experimentally verify the analytical findings, demonstrating 112 Gb/s POLMUX-QPSK transmission with Coherent Detection in a non-fading free-space channel, and numerically extend the experimental results to turbulent settings by invoking the lognormal model for turbulence-induced fading. Performance gains of 5-14 dB along with a doubling of the data rate through polarization multiplexing are exhibited compared to legacy single-polarization intensity modulation/direct Detection (IM/DD) optical wireless systems. The presented analytical and experimental results indicate that the proposed approach is promising for notably increasing the data rate in last-mile free-space optical transmission.
Ajay Nahata - One of the best experts on this subject based on the ideXlab platform.
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Coherent Detection of pulsed narrowband terahertz radiation
Applied Physics Letters, 2006Co-Authors: Hua Cao, Ajay NahataAbstract:We demonstrate the generation and Coherent Detection of narrowband terahertz radiation using a Q-switched laser pumped optical parametric oscillator as the optical source. Narrowband terahertz radiation is produced using conventional difference frequency mixing and Coherently detected via a frequency domain technique that relies on Coherent upconversion of the terahertz field combined with optical homodyning to suppress background noise. GaSe crystals are used for both generation and Coherent Detection processes. Although we provide a proof-of-principle demonstration at 2THz, the infrared radiation may be tuned from the far-infrared through the midinfrared by simply tuning the idler wavelength of the optical parametric oscillator and the orientation of the two crystals.
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Coherent Detection of Tunable Narrowband Far-Infrared Radiation
Optical Terahertz Science and Technology, 2005Co-Authors: Ajay NahataAbstract:We demonstrate the Coherent Detection of tunable narrowband far-infrared radiation. This radiation is produced using conventional difference frequency mixing and detected using the linear electro-optic effect. The technique can be straightforwardly extended to the mid-infrared.
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Generation and Coherent Detection of far-infrared and mid-infrared radiation
The 15th Annual Meeting of the IEEE Lasers and Electro-Optics Society, 2002Co-Authors: Ajay Nahata, R.a. Linke, T.f. HeinzAbstract:We describe nonlinear optical techniques for the generation and Coherent Detection of femtosecond electromagnetic pulses. We demonstrate that poled polymers are particularly attractive materials for this application.
Boris Voronov - One of the best experts on this subject based on the ideXlab platform.
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On-chip Coherent Detection with quantum limited sensitivity
Scientific Reports, 2017Co-Authors: Vadim Kovalyuk, Simone Ferrari, Oliver Kahl, Alexander Semenov, Michael Shcherbatenko, Yury Lobanov, Roman Ozhegov, Alexander Korneev, Nataliya Kaurova, Boris VoronovAbstract:While single photon detectors provide superior intensity sensitivity, spectral resolution is usually lost after the Detection event. Yet for applications in low signal infrared spectroscopy recovering information about the photon’s frequency contributions is essential. Here we use highly efficient waveguide integrated superconducting single-photon detectors for on-chip Coherent Detection. In a single nanophotonic device, we demonstrate both single-photon counting with up to 86% on-chip Detection efficiency, as well as heterodyne Coherent Detection with spectral resolution f/∆f exceeding 10^11. By mixing a local oscillator with the single photon signal field, we observe frequency modulation at the intermediate frequency with ultra-low local oscillator power in the femto-Watt range. By optimizing the nanowire geometry and the working parameters of the Detection scheme, we reach quantum-limited sensitivity. Our approach enables to realize matrix integrated heterodyne nanophotonic devices in the C-band wavelength range, for classical and quantum optics applications where single-photon counting as well as high spectral resolution are required simultaneously.
Neda Cvijetic - One of the best experts on this subject based on the ideXlab platform.
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polarization multiplexed optical wireless transmission with Coherent Detection
Journal of Lightwave Technology, 2010Co-Authors: Neda Cvijetic, Dayou Qian, Yuekai Huang, Ting WangAbstract:In this paper, we propose, analyze, and experimentally verify polarization-multiplexed optical wireless transmission with Coherent Detection as a means of improving performance and increasing the per-wavelength data rate in the presence of atmospheric turbulence. It is first shown that in terrestrial last-mile applications, the polarization state changes of the optical wireless signal are governed by optical source properties both in the absence and in the presence of mild to moderately severe turbulence. Under these conditions, it is shown that the polarization evolution is reduced to a polarization state rotation wherein the cross-polarization interference can be equalized with well-known blind algorithms. We also experimentally verify the analytical findings, demonstrating 112 Gb/s POLMUX-QPSK transmission with Coherent Detection in a non-fading free-space channel, and numerically extend the experimental results to turbulent settings by invoking the lognormal model for turbulence-induced fading. Performance gains of 5-14 dB along with a doubling of the data rate through polarization multiplexing are exhibited compared to legacy single-polarization intensity modulation/direct Detection (IM/DD) optical wireless systems. The presented analytical and experimental results indicate that the proposed approach is promising for notably increasing the data rate in last-mile free-space optical transmission.
Li Jun - One of the best experts on this subject based on the ideXlab platform.
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Research and Implementation with CPLD of Polyphase Filtering in Quadrature Coherent Detection of IF Sampling
Radar & Ecm, 2003Co-Authors: Li JunAbstract:The quadrature Coherent Detection is widely used in signal processing field, since it can reserve all information of the complex envelope of signal. This paper presents a digital quadrature Coherent Detection realization with the ployphase filtering, and the ASIC design of quadrature interpolator based on CPLD. The results show this method can satisfy the requirements of high performances of signal processing.