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Presentations
Dr. Frederick Finkelberg Founder; Light Fantastic Technologies Ms. Rose Zanouz Marketing Director - Light Fantastic Technologies Topic: DreamSpace; Assuring Continued Technology Leadership
Dr. Valencia Joyner Director of Advanced Integrated Circuits and Systems Laboratory and Assistant Professor of Electrical and Computer Engineering at Tufts University Topic: Monolithic, Multi-Gb/s Imaging Receivers in CMOS for Visible Light Communication This project presentation will discuss research conducted by the Tufts Advanced Integrated Circuits and Systems Lab on the design of optoelectronic VLSI systems combining photonic and nano-electronic silicon devices in a system-on-chip approach to achieve new levels of performance in high-speed communication and sensing. Optical MIMO (multi-input/multi-output) systems are emerging as a disruptive wireless access technology with the potential to overcome challenges faced by free-space optical (FSO) links in delivering on the promise of unlimited-bandwidth wireless channels. The use of source/detector arrays in optical MIMO processing combined with space-time coding to increase channel capacity and spectral efficiency is the sought-after solution to performance-limiting factors of FSO, namely fading due to scintillation and alignment requirements. We will present collaborative research work to design, develop, and implement a new class of power-efficient integrated photo-receivers. The architecture is based on an imaging diversity receiver approach, combining planar tessellated photo-detectors with mixed-signal integrated CMOS circuits using 3D integration methods for optical MIMO demonstrations at bit rates > 70Gb/s. We will present work on the design and optimization of multi-channel receiver circuit arrays on a single silicon chip considering the competing trade-offs of gain, power, dynamic range, and noise performance at multi-GHz channel bandwidths. Front-end, low-noise amplifier topologies incorporating automatic gain control and capacitive-feedback circuits that are insensitive to detector capacitance variation will be presented. To exploit the spatial diversity of MIMO receivers, we will describe on-chip signal processing circuit architectures to improve receiver output signal-to-noise ratio, bit-error rate performance, and power efficiency. Experimental and simulated results on custom chip implementations in state-of-the-art 180nm and 90nm CMOS processes will be described.
Dr. Mohsen Kavehrad W.L. Weiss Professor of Electrical Engineering and CICTR Founding Director, The Pennsylvania State University Topic: Optical Wireless Networked-Systems for Communications, Navigation and Imaging with Optimized Transceivers. This project presentation focuses on leveraging the progress in semiconductor technology to facilitate production of efficient light-based communications, navigation, sensing, and imaging techniques. Investigation of energy-efficient, miniaturized transceivers will create a wireless medium, both indoors and outdoors, providing enhanced imaging resolution, accurate navigation and pointing capabilities, and improved quality-of-service for indoor and outdoor communications links. The applications will seamlessly inter-connect multiple intelligent devices in a network that is easily deployable in automobiles and aircraft navigation systems, on-board sensor and entertainment data delivery systems, and high-definition audio-visual broadcasting systems. The superiority of wireless optical multi-input multi-output (MIMO) communication transceivers employing Multi-Spot Diffuse Transmitter and Imaging Fly-Eye Receiver, inspired by Kavehrad & Yun, is the fundamental solution to combating spatial, angular and temporal dispersions in communication and active imaging systems. The key is to select the Field-of-View (FoV) of diversity receiver branches appropriately. Several networking issues have to be taken into consideration in view of the line-of-sight and diffuse physical link architectures. Joint optimization of individual network components need to be carried out to guarantee optimal performance in terms of power saving, data rate, imaging resolution, and pointing accuracy. Network topologies and link protocols need development and testing for indoor and outdoor propagation scenarios, both in presence and absence of scattering and turbulence. Light propagation through turbid and turbulent atmosphere is a well-understood phenomenon, but proper selection of system variables is essential for mitigation of these adverse effects. This presentation addresses the challenges of integrating optimized optical devices in the variety of environments described above, and presents mitigation and tailoring approaches for a multi-purpose optical network.
Dr. William P. Krug Boeing Associate Technical Fellow (ATF), Boeing Research and Technology Dr. Eric Y. Chan Boeing Technical Fellow (TF), Boeing Research and Technology Topic: Optical Wireless for Aerospace Applications This panel presentation will highlight where the aerospace industry is already leveraging efficient visible LED light source arrays, to replace conventional lighting with much more power efficient visible light LEDs (VL-LEDs). Their use is leading to energy savings and improved reliability for cabin lighting in commercial aircraft. To further reduce size, weight, and energy consumption for communications, distributed sensing, and control systems, there is significant interest in approaches to eliminate the need for separate power and data distribution wiring harnesses within aerospace platforms. This includes data over power schemes to modulate VL-LED lighting that combine power distribution and optical wireless communications across a single infrastructure, as originally suggested at Penn State. This panel presentation will describe an experimental implementation of a WLED transceiver by retrofitting low cost COTS WLED into standard optical transceivers, to demonstrate error free free-space operation at 10 Mb/s, correlated with simulations that show practical scaling for cabin environments. The benefits and issues to the potential use of laser and VL-LED based optical wireless, MIMO, radio over fiber and 60 GHz wireless communications for potential aerospace applications will be described.
Dr. Joseph Marron Lockheed Martin Technical Fellow, Lockheed Martin Coherent Technologies Topic: Coherent Optical Imaging Systems Advances in detector arrays, lasers and processor technologies have enabled new methods for imaging based on coherent detection. With coherent detection, one can measure the amplitude and phase of the optical field scattered by an object rather than the intensity as with conventional optical imaging sensors. In this manner, we are able to apply digital signal processing methods developed for radar systems to the optical regime and thus perform advanced functions such as digital atmospheric turbulence correction and interferometric 3D imaging. Turbulence correction is important in long-range imaging where the atmosphere imparts phase errors that degrade imaging performance. With coherent imaging, one can correct for such phase errors digitally by applying autofocus methods based on maximizing image sharpness. Experimental results are presented that demonstrate image recovery in the presence of strong turbulence. 3D imaging with coherent data is accomplished by computing the phase difference of images recorded at different wavelengths in a manner analogous to interferometric SAR. Examples of 3D images obtained by long-range interferometric imaging are also presented.
Dr. David T. Neilson
Technical Manager,
Efficient Network Technology Group,
Topic: Energy Efficient
Communication and the GreenTouch Consortium
Increased energy efficiency
for communications networks is critical to a sustainable Internet.
The GreenTouch
Consortium seeks to bring together industry, academia and other nonprofits
to
Dr. Anthony Ng’oma Senior Research Scientist, Corning Incorporated
Topic:
Radio-over-Fiber Solutions for In-building The presentation will discuss the challenges and techniques for realizing high-throughput wireless communication. Picocellular network designs at lower frequencies up to 6 GHz will be compared to implementations at mm-wave frequencies (i.e. 60 GHz). Theoretically and experimental results from promising MIMO implementation approaches that avoid the duplication of RoF links will be presented. Implementations of simple RoF system architectures using unlicensed frequency spectrum at 60 GHz to deliver multi-Gbps (>20 Gb/s) wireless capacity will be presented.
Mr. Daniel E. Raible Electronics Engineer, NASA’s Glenn Research Center
Topic:
Optical Communications
Technologies at NASA Glenn Research Center This presentation will provide an overview of several previous and current research efforts performed at NASA Glenn in support of optical communications, such as photovoltaic powered modulating retro reflectors, liquid crystal based beam steering for phased array antennas and fiber optic avionics networks. Application to meet the agency’s potential future optical needs, as driven by mission requirements stemming from near earth, deep space and planetary optical terminals with broadband streaming video capabilities will be discussed.
Dr. Richard D. Roberts Wireless Research Scientist, Intel Labs - Oregon Topic: Visible Light Communications (VLC): Intel Labs Perspective on the Automotive Use Case In this panel presentation, Intel Labs presents a vision for optical wireless communications, in particular VLC (visible light communications). The presentation starts by pointing out that LED lighting is becoming ubiquitous and these LED signal sources of opportunity have a useful modulation bandwidth. Next we present some intuitive potential applications with emphasis on VLC finding its natural solution space. Intel Labs has a strong interest in the application of VLC to Intelligent Traffic Systems and several key research challenges are presented in this area. We then discuss the need for standards and how standards facilitate markets, and in particular an introduction is made to the on-going work at IEEE802.15.7.
Mr. Scott Thompson President, OBERON Inc. - State college, PA. Topic: Optical Wireless Adaptors for Multimedia Services This panel presentation will describe the current state of the art for connecting “computing devices” to “display devices”, and describe opportunities for optical wireless adaptors as the ultimate interface for high definition multi-media services. Multimedia services are the processing and communication of image, audio and text in real time. More mobile devices are being used to deliver and share multimedia services. These devices currently represent the perfect vehicle for the convergence of Telecommunication and Computer Communication. This convergence leads to new rich multimedia interfaces for services like Videoconference, Tele-presence, Immersion, Collaboration on medical images, and Gaming. This is an emerging business, and the need for new products is evident.
Dr. Zhengyuan (Daniel) Xu Professor of Electrical Engineering and Director of the Multi-campus Center for Ubiquitous Communication by Light (UC-Light), University of California, Riverside. Topic: LED-based Optical Wireless Communication Performance Study This project presentation focuses on communications via ultraviolet lighting LEDs. The abundant unlicensed visible and ultraviolet (UV) spectra offer tremendous opportunities for high data rate wireless services at low power and low cost. These have been recently enabled by significant advances in UV and lighting LEDs, optical detectors, and filters in the visible light and UV bands. This presentation will first provide a comprehensive overview of relevant state-of-the-art optical devices, LED-based indoor and outdoor optical wireless communication systems, channel modeling and measurement techniques. Particularly it will introduce unique solar-blind non-line-of-sight UV scattering communications as well as piggybacking communications by illuminating LEDs. It will then discuss open issues and suggest future R&D directions using those tiny semiconductor devices.
Poster Presentations
K.Cui, G.Chen, Zh. Xu - University of California, Riverside R. D. Roberts - Intel Labs
With the emergence of high lumen output white lighting LEDs, visible light communication has become an intriguing technology to realize low cost data transmission in conjunction with lighting. This poster presentation focuses on some key issues in practical line-of-sight (LOS) visible light communication system design. They include a transmitter, channel model, and receiver front-end. A transmitter containing white LED arrays is designed to achieve required lighting distribution and simultaneous reliable data transmission. A basic LOS channel model to facilitate the link budget analysis is presented for optimization of the receiver under major noise sources. Some experimental results based on a practical indoor communication system are also demonstrated.
J. Fadlullah, M. Kavehrad
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The Pennsylvania State University Topic: Gbps Digital Transmission on Indoor Infrared Links The main objective of the presented research is to characterize an indoor wireless optical communication channel. Until recently, there have not been any comprehensive published measurements results presenting characteristics of this channel for high data rates, e. g. 1Gbit/s. To this end, a measurement setup is implemented, with a high-power laser diode acting as the optical transmitter and an avalanche photodiode acting as the receiver. Using a network analyzer, the laser is modulated by CW frequencies up to 1 GHz, which is the bandwidth of the receiver, as limited by the intrinsic capacitance and the response-time of the avalanche photodiode. A single collimated optical spot with a small elliptical shape on the ceiling is tested. The impacts of receiver orientation and configuration on the channel frequency response are investigated. These measurements will enable us to explore the possibility of higher data transmission rates, potentially beyond 1 Gbps, on indoor optical wireless channels. These channels can be a viable alternative to inherently insecure and interference-prone RF wireless channels, and therefore, could be the basis of next-generation high data rate wireless local area networks.
J. Fadlullah, M. Kavehrad -
The Pennsylvania State University Z. Hajjarian - Harvard University Topic: Trends of Optical Wireless (Laser) Applications in Biomedical Research This poster presentation will explore trends in biomedical applications of optical wireless. Lasers are increasingly being used to diagnose, treat, and image living body tissues. The collimated beam properties, as well as small beam-width, has facilitated accurate surgery with lasers. LASIK (Laser-Assisted In situ Keratomileusis) for precise and controlled removal of corneal tissue to correct eye-lens focusing and laser cataract surgery are very common applications. Since laser applies a focused beam of high intensity, cutting and cauterizing of surgical incisions have become less time consuming and more efficient. Imaging techniques such as diffuse optical tomography and optical coherence tomography to create 3D images of soft tissues have also been developed with ultra-fast lasers. Spectroscopic techniques have been applied to lasers which allow performing non-invasive 'optical' biopsy of tissues. Lasers also have certain properties such as the 'trapping' effect which has been demonstrated to control chemical reactions. As a result, in cancer treatment, lasers can be used to shrink and destroy tumors, as well as identifying them. Photodynamic therapy is another application where lasers are used in conjunction with photosensitizing agents to treat cancerous organs. With advance in ultra-short pulsed lasers and ultra-short pulse shaping techniques, it is definitely possible to construct higher resolution biomedical imaging equipments. In the near future, optical 'tweezers' would be able to isolate constituents of individual cells and trigger reactions in them. Successful development of these and other laser applications would give biomedical researchers new improved tools for better diagnostics, treatment and imaging capability for currently incurable diseases such as cancer.
Q. He, Zh. Xu - University of California, Riverside B. M. Sadler - Army Research Lab Topic: Performance Limits for Wireless Ultraviolet Communications The poster presentation explores the achievable performances of wireless ultraviolet communication systems based on the experimental results of path loss and impulse response measurements. Especially, specific models for photo-detectors such as photomultiplier tubes and avanlanche photodiodes and modulation formats are considered. While the primary motivation is to provide semi-analytical projections on the achievable communication performance, the results and approaches can serve as the first-hand basis for the system design. Future work includes investigation on the statistics of the channel random variation due to scattering and possible turbulence, as well as study of link outage probability.
T. Kane -
The Pennsylvania State University Topic: Underwater Optical Communications This poster presentation will explore current and past efforts in underwater optical communications, as well as future thrusts. The emphasis will be on understanding the impact of turbidity on the communication channel, and how to mitigate its detrimental effect. The challenge of air-to-sea communication links will be included as well. The ultimate goal of this presentation will be to stimulate discussion amongst workshop participants, in hopes of identifying specific technical and theoretical challenges which will need to be overcome in order to enable practical operations of underwater optical communications.
M. Kavehrad - The Pennsylvania State University
Y. A. Alqudah Topic: Broadband Indoor Optical Wireless Communications Angle diversity is an effective technique to compensate for multipath temporal dispersion in a wireless infrared environment. Diversity is accomplished by using a multi-branch receiver capable of resolving multipath. The goal of this poster is to illustrate the effect that increasing the diversity order of the receiver has on the performance of the link in a Multi-Spot-Diffusing Configuration (MSDC) with combining techniques. Outage probability based on probability of bit error is adopted as performance measure. It is shown that there is an optimal number of branches, which meets the performance criteria. This number depends on the choice of branch field-of-view (FOV).
M. Kavehrad - The Pennsylvania State University
Topic: Ultra-Short Pulsed FSO Communication System with Fractal Modulation Wireless optical communications is one of the most promising candidates for future broadband communications, offering transmission rates far beyond possible by RF technology. Free Space Optical Communication through cloud-obscured channels suffers from severe degradations due to multi-scattering, which induces delay spread in the received signal. The delay spread of FSO channel can vary considerably according to channel conditions, varying from nanoseconds to microseconds under clear and cloudy channel conditions, respectively. These changes can occur gradually as in the case of a cloud overcast clearing off, or abruptly as in the case of scattered clouds. In order to maximize channel throughput, powerful modulation schemes need to be employed and provide reliable communications. Multi-rate communications using fractal modulation has received wide attention in the research community, as an efficient mean to provide reliable communications. Additionally, optimum pulse shaping has been shown to be a crucial element in optimizing system performance. In this poster, we present a new approach to wireless optical communications, where we combine multi-rate communications with short-pulsed RZ modulation. We show that multi-rate communications provide diversity against channel degradation and fluctuation, while RZ modulation is more robust to dispersive channel effects in comparison to NRZ modulation, thus providing an overall improvement in system performance, reliability and availability.
M. Kavehrad, J. Fadlullah
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The Pennsylvania State University Z. Hajjarian - Harvard University Topic: Active Laser Imaging in Obscurrants and Turbulance using MIMO structure Inspired by Kavehrad & Yun’s multi-spot diffuse indoor wireless optical communications link, a spatially multiplexed MIMO imaging system is proposed and the corresponding performance and image quality is analyzed in a turbid and turbulent atmosphere. Implementation issues are of interest in this investigation.
M. Kavehrad - The Pennsylvania State University Z. Hajjarian - Harvard University A. Enteshari - Starkey Laboratories Topic: Optical Wireless Networking On-board Planes and Energy-Efficient LEDs Power-line communication on Smart-Grid has advanced through last decade and it is going to be a mature technique in near future. Meanwhile, optical wireless communication through energy-efficient lighting LEDs has been investigated, recently. In this poster presentation, it is shown that marriage of these two techniques creates a convenient energy-efficient delivery mechanism for fulfilling the promise of broadband access on-board an aircraft, while providing efficient lighting. The potential capabilities of these two emerging techniques are examined.
J. Liao, Z.R. Huang - Rensselaer Polytechnic Institute A. Mirvakili, V. Joyner – Tufts University A. Boryssenko – Univ. of Massachusetts, Amherst Topic: Dual-Mode RF/Optical Transceiver Modules for Hybrid Wireless Networks The unlimited bandwidth free-space optical (FSO) signaling and high mobility RF transmissions are the two major choices for wireless communication interconnects. The RF/Optical hybrid communication systems demonstrate increased bandwidth, reduced power consumption, low cost, and high reliability to dynamic operational environment. Hybrid system interconnect realization requires advanced integration and packaging techniques to account for several orders of dimensional discrepancy between antenna geometries measured in millimeters at microwaves and typical sub-millimeter dimensions of active optical components. Here we report results of ongoing multi-university research efforts in the design, development, and testing of miniaturized dual-mode transceiver modules for high-speed, hybrid RF/Optical wireless communications. Two novel hybrid packaging schemes using two different microwave printed antennas (quasi-Yagi antenna and microstrip patch antenna) are explored. RF and FSO front-end elements are integrated on a planar compact printed circuit board (PCB) with shared electrical and structural components. Simulated and experimental results are presented to determine signal degradation, bit error rate performance, and decoupling between the physically collocated RF and FSO channels with a date rate of 2.5 Gbps for the FSO link in a 10 GHz RF environment.
Zh. Liu
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The Pennsylvania State University Topic: Optical Wireless Communication Using White Light Supercontinuum This poster presentation focuses on super-continuum which is very unique in that it has high spatial coherence and covers an extremely broad wavelength range. Due to its high spatial coherence white light super-continuum can be collimated into a highly directional laser-like beam for optical wireless applications. The large bandwidth of super-continuum can bring unprecedented multiplexing capability to optical information systems. We will discuss super-continuum and its potential applications such as spectroscopy, communication, and imaging.
T.E. Vandervelde - Tufts University Topic: Novel Materials for Communication Wavelengths This poster presentation focuses on novel materials. High-quality, low-cost, infrared materials are hard to come by. At present, we most commonly use either strained II-V materials, which can lead the a significant number of defects being formed, or a mercury-cadnium-telluride compound, which is not only toxic by has a high degree of spatial non-uniformity in the crystal dramatically lowering device yield and increasing cost. The lack of reliable strain-free epi-materials (i.e. lattice matched to a substrate) for many of the infrared wavelengths in the III-V or Group-IV systems has become a stumbling block on the road to future technological progress. Here, we report on the efforts of the Renewable Energy and Applied Photonics (REAP) Labs to solve these problems. We are addressing this issue with three potential materials solutions: 1) the introduction of Thallium into standard InGaAs and InGaP compounds to extend their wavelength response; 2) the use of novel type-II strained-layer super-lattices; and 3) the application of SiGeSn to achieve direct band gap devices in the Group-IV materials systems. Prof. Vandervelde will discuss the advances made in each of these areas and describe their future promise as well.
S. Yin -
The Pennsylvania State University Topic: Smart Optical Transmitter, Beam Controller, and Receiver for Optical Wireless Communications / Imaging The objective of this project is to develop smart optical transmitters and receivers for the next generation high speed, high reliability optical wireless communications and imaging. The major challenges for high speed optical wireless communications and imaging include a weak optical signal from the scattered light and the cross-talk noise from the multi-path reflections. To overcome these fundamental limitations, in this project, we will develop smart optical transmitter and receiver, which have following unique properties:
Sh. You, M. Kavehrad – The Pennsylvania State University Topic: Pulse Shaping by Liquid Crystal-Spatial Light Modulator for Optical Wireless Communications We demonstrated programmable optical pulse shaping of femto-second laser pulse by using Liquid Crystal-Spatial Light Modulator (LC-SLM). With a combination of amplitude and phase mask in LC-SLM, arbitrarily shaped ultra-short pulse waveforms could be synthesized by manipulating the frequency components which are spatially dispersed in the high-resolution zero-dispersion pulse shaping system. The specified shaped pulses, Square Root Raised Cosine (SRRC) and Meyer wavelet, are generated through the programmable pulse shaping system, which can potentially improve the performance of free-space optical wireless communications system, for transmission through obscurant such as clouds.
R. Yun, V. Joyner – Tufts University Topic: Low-Power, 10-Gb/s Optical Receivers in 180nm CMOS Low-power, small footprint multi-Gb/s optical receivers are important circuit blocks for optical communications, high-speed optical I/O and multi-channel optical MIMO system applications. However, overcoming competing trade-offs to achieve low-power, high sensitivity, and high-speed performance in CMOS is a design challenge. This work presents the design of a 10Gb/s optical receiver in a low-cost 180nm CMOS process. The optical receiver chip occupies a 1mm x 1mm area with the core TIA active area, excluding decoupling capacitors, of 25um x 40um due to the inductor-less design. The TIA is evaluated by assembling a high-speed PIN photodiode (capacitance = 200fF, responsivity=0.86A/W at 1550nm), TIA, and bypass capacitors in a small TO-46 package to facilitate high frequency optical measurement. The measured trans-impedance gain is 62dBΩ.
R. Yun, V. Joyner – Tufts University Topic: CMOS Optical Sensors with Phase and Amplitude Sensitivity for Near-Infrared Biomedical Imaging Optical techniques are rapidly advancing as cost-effective and efficacious tool for in vivo characterization of the physiological state of tissue. The benefits of optical spectroscopy lie in the wavelength-dependent absorption, scattering, and delay experienced as photons travel through tissue and encounter molecules along the path. Time resolved near-infrared (NIR) spectroscopy in the frequency domain, where the light source intensity is sinusoidally modulated, allows explicit separation of tissue absorption and scattering coefficients. We present the design and measurement results of a fully integrated optical sensor for phase and amplitude detection of RF-modulated (~110MHz) optical signals for use in portable/wearable frequency-domain spectroscopy instruments. The sensor consists of a NIR-sensitive photo-detector monolithically integrated with front-end analog amplifier and signal processing circuitry for amplitude and phase detection. A high-gain low-noise differential trans-impedance amplifier (TIA) is implemented at the front-end for photocurrent-to-voltage conversion. A continuous-time comparator-based phase detector is employed with a measured average phase resolution of 4.8mV/degree and 255 µVrms output noise. The amplitude response exhibits 2.2mV/µW resolution with 0.4% linearity. The measured amplitude output noise is 72 µVrms. The sensor is implemented in an unmodified 180nm CMOS technology and consumes 23.4mW from a 1.8V supply voltage.
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