The Experts below are selected from a list of 100824 Experts worldwide ranked by ideXlab platform
Xiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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high speed acoustic communication with orbital angular momentum multiplexing
Journal of the Acoustical Society of America, 2017Co-Authors: Chengzhi Shi, Marc Dubois, Yuan Wang, Xiang ZhangAbstract:Acoustic communication is critical for underwater application such as deep ocean scientific explorations, off-shore industrial controls, and ocean environment monitoring. This is because other techniques using electromagnetic waves such as RF communications are difficult for underwater applications due to the strong absorption of water in such a frequency. Optical communication, on another hand, suffers from the light scattering from micro-particles or marine life making long range underwater optical communication very challenging. Therefore, using acoustic waves to transmit information is currently the dominate technique for underwater applications including Data collection and remote control of off-shore benthic stations. However, the low frequency bandwidth available for acoustic communication limits the Data Transmission Rate and information capacity or content. We propose and experimentally demonstRate here a new approach using the orbital angular momentum (OAM) of acoustic vortex beams which provide...
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high speed acoustic communication by multiplexing orbital angular momentum
Proceedings of the National Academy of Sciences of the United States of America, 2017Co-Authors: Chengzhi Shi, Marc Dubois, Yuan Wang, Xiang ZhangAbstract:Long-range acoustic communication is crucial to underwater applications such as collection of scientific Data from benthic stations, ocean geology, and remote control of off-shore industrial activities. However, the Transmission Rate of acoustic communication is always limited by the narrow-frequency bandwidth of the acoustic waves because of the large attenuation for high-frequency sound in water. Here, we demonstRate a high-throughput communication approach using the orbital angular momentum (OAM) of acoustic vortex beams with one order enhancement of the Data Transmission Rate at a single frequency. The topological charges of OAM provide intrinsically orthogonal channels, offering a unique ability to multiplex Data Transmission within a single acoustic beam geneRated by a transducer array, drastically increasing the information channels and capacity of acoustic communication. A high spectral efficiency of 8.0 ± 0.4 (bit/s)/Hz in acoustic communication has been achieved using topological charges between −4 and +4 without applying other communication modulation techniques. Such OAM is a completely independent degree of freedom which can be readily integRated with other state-of-the-art communication modulation techniques like quadrature amplitude modulation (QAM) and phase-shift keying (PSK). Information multiplexing through OAM opens a dimension for acoustic communication, providing a Data Transmission Rate that is critical for underwater applications.
Ian H. White - One of the best experts on this subject based on the ideXlab platform.
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Towards 10 Gb/s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED
Photonics Research, 2017Co-Authors: Mohamed Sufyan Islim, Shaun Viola, Nikolaos Bamiedakis, Scott Watson, Xiangyu He, R. Ferreira, Stefan Videv, R.v. Richard V. Penty, Ian H. WhiteAbstract:Visible light communication (VLC) is a promising solution to the increasing demands for wireless connectivity. Gallium nitride micro-sized light emitting diodes (micro-LEDs) are strong candidates for VLC due to their high bandwidths. Segmented violet micro-LEDs are reported in this work with electrical-to-optical bandwidths up to 655 MHz. An orthogonal frequency division multiplexing-based VLC system with adaptive bit and energy loading is demonstRated, and a Data Transmission Rate of 11.95 Gb/s is achieved with a violet micro-LED, when the nonlinear distortion of the micro-LED is the dominant noise source of the VLC system. A record 7.91 Gb/s Data Transmission Rate is reported below the forward error correction threshold using a single pixel of the segmented array when all the noise sources of the VLC system are present.
Mohamed Sufyan Islim - One of the best experts on this subject based on the ideXlab platform.
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deep uv micro led arrays for optical communications
International Conference on UV LED Technologies & Applications Conference (ICULTA-2018), 2018Co-Authors: Xiangyu He, Mohamed Sufyan Islim, Jonathan James Donald Mckendry, Er Dan Gu, Ardimas Andi Purwita, Harald Haas, M.d. DawsonAbstract:Deep ultraviolet (UV) optical communications have attracted considerable attention recently. As most of the Sun's ultraviolet radiation is absorbed by the ozone layer in Earth's stratosphere, UV optical communications offer not only a high-security communication link between satellites in the upper atmosphere, but also Data Transmission with low solar background noise for outdoor communication on the ground. Furthermore, deep UV light is strongly scattered in the air caused by abundant molecules and aerosols, which enables non-line-of-sight short-range optical communication. However, in comparison with visible light communications, the Data Transmission Rate based on deep UV light emitting diodes (LEDs) has been little explored and is still quite low. This is mainly due to the low modulation speed of conventional deep UV-LEDs. Therefore, developing high speed deep UV-LEDs is of paramount importance. In recent years, we have developed the micro-LEDs (µLEDs) as novel high-speed transmitters for visible light communications.1 These µLEDs, of edge dimension/diameter typically in the 10-100µm range, have extremely high modulation bandwidths due to their high operating current densities. Based on these studies, we report here the first III-nitride deep UV-µLED array emitting at around 262 nm to demonstRate its full potential for deep UV optical communications. This array consists of 15 µLED elements with a flip-chip configuration. With an emission area of 565.5 µm2, each µLED element is individually addressable. The UV optical power of a single µLED element is 196 µW at 3.4 kA/cm2 direct-current (DC) operating current density. We are currently measuring the modulation bandwidth of these deep UV-µLEDs. As they can sustain such a high DC operating current density, we expect a high modulation bandwidth and, in turn, a high Data Transmission Rate for fast free-space optical communication. These results will be presented in the conference.
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Towards 10 Gb/s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED
Photonics Research, 2017Co-Authors: Mohamed Sufyan Islim, Shaun Viola, Nikolaos Bamiedakis, Scott Watson, Xiangyu He, R. Ferreira, Stefan Videv, R.v. Richard V. Penty, Ian H. WhiteAbstract:Visible light communication (VLC) is a promising solution to the increasing demands for wireless connectivity. Gallium nitride micro-sized light emitting diodes (micro-LEDs) are strong candidates for VLC due to their high bandwidths. Segmented violet micro-LEDs are reported in this work with electrical-to-optical bandwidths up to 655 MHz. An orthogonal frequency division multiplexing-based VLC system with adaptive bit and energy loading is demonstRated, and a Data Transmission Rate of 11.95 Gb/s is achieved with a violet micro-LED, when the nonlinear distortion of the micro-LED is the dominant noise source of the VLC system. A record 7.91 Gb/s Data Transmission Rate is reported below the forward error correction threshold using a single pixel of the segmented array when all the noise sources of the VLC system are present.
Steven P Denbaars - One of the best experts on this subject based on the ideXlab platform.
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2 gbit s Data Transmission from an unfiltered laser based phosphor converted white lighting communication system
Optics Express, 2015Co-Authors: Chao Shen, Michael Cantore, Robert M Farrell, James S Speck, Shuji Nakamura, Hassan M Oubei, Bilal Janjua, Tien Khee Ng, Munir M Eldesouki, Steven P DenbaarsAbstract:We demonstRate Data Transmission of unfiltered white light geneRated by direct modulation of a blue gallium nitride (GaN) laser diode (LD) exciting YAG:Ce phosphors. 1.1 GHz of modulation bandwidth was measured without a limitation from the slow 3.8 MHz phosphor response. A high Data Transmission Rate of 2 Gbit/s was achieved without an optical blue-filter using a non-return-to-zero on-off keying (NRZ-OOK) modulation scheme. The measured bit error Rate (BER) of 3.50 × 10−3 was less than the forward error correction (FEC) limit of 3.8 × 10−3. The geneRated white light exhibits CIE 1931 chromaticity coordinates of (0.3628, 0.4310) with a color rendering index (CRI) of 58 and a correlated color temperature (CCT) of 4740 K when the LD was opeRated at 300 mA. The demonstRated laser-based lighting system can be used simultaneously for indoor broadband access and illumination applications with good color stability.
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4 gbps direct modulation of 450 nm gan laser for high speed visible light communication
Optics Express, 2015Co-Authors: Changmin Lee, John E Bowers, Chong Zhang, Michael Cantore, Robert M Farrell, Tal Margalith, James S Speck, Shuji Nakamura, Steven P DenbaarsAbstract:We demonstRate high-speed Data Transmission with a commercial high power GaN laser diode at 450 nm. 2.6 GHz bandwidth was achieved at an injection current of 500 mA using a high-speed visible light communication setup. Record high 4 Gbps free-space Data Transmission Rate was achieved at room temperature.
Scott Watson - One of the best experts on this subject based on the ideXlab platform.
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Towards 10 Gb/s orthogonal frequency division multiplexing-based visible light communication using a GaN violet micro-LED
Photonics Research, 2017Co-Authors: Mohamed Sufyan Islim, Shaun Viola, Nikolaos Bamiedakis, Scott Watson, Xiangyu He, R. Ferreira, Stefan Videv, R.v. Richard V. Penty, Ian H. WhiteAbstract:Visible light communication (VLC) is a promising solution to the increasing demands for wireless connectivity. Gallium nitride micro-sized light emitting diodes (micro-LEDs) are strong candidates for VLC due to their high bandwidths. Segmented violet micro-LEDs are reported in this work with electrical-to-optical bandwidths up to 655 MHz. An orthogonal frequency division multiplexing-based VLC system with adaptive bit and energy loading is demonstRated, and a Data Transmission Rate of 11.95 Gb/s is achieved with a violet micro-LED, when the nonlinear distortion of the micro-LED is the dominant noise source of the VLC system. A record 7.91 Gb/s Data Transmission Rate is reported below the forward error correction threshold using a single pixel of the segmented array when all the noise sources of the VLC system are present.
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high bandwidth parallel Data Transmission using gan cmos micro led arrays
IEEE Photonics Conference, 2012Co-Authors: Shuailong Zhang, Andrew Cogman, Jonathan James Donald Mckendry, Scott Watson, A.e. Kelly, Er Dan Gu, David Massoubre, Robert Henderson, M.d. DawsonAbstract:A multiple-channel visible light communication demonstration system is realized through a CMOS-controlled micro light-emitting diode (μLED) array. A total Data Transmission Rate of 1.5 Gbit/s is achieved by modulating four μLED pixels simultaneously.
