Innovations in Optics-Based Communications

Researchers will announce some of the latest breakthroughs and innovations in optics-based communications at OFC/NFOEC 2006--the largest and most comprehensive international event for optical communications.

OFC/NFOEC (Optical Fiber Communication Conference and Exposition/National Fiber Optic Engineers Conference) will take place at the Anaheim Convention Center between March 5 and 10, 2006.

In addition to a technical conference that spans the whole meeting, there will be an exposition featuring the latest in optical technology from more than 600 of the industry's key companies. The meeting is sponsored by the IEEE Communications Society, the IEEE Lasers and Electro-Optics Society, and the Optical Society of America.

TECHNICAL PRESENTATION HIGHLIGHTS

The following represent some of the technical highlights at OFC/NFOEC 2006.

1. Making Internet-Based Television Practical and Affordable
2. Pinpointing Structural Problems Earlier With Fiber Optics
3. Delivering Super-Broadband Wired and Wireless Services Simultaneously
4. E-Science: The Future Of Sharing Data
5. Thinking Inside the Box
6. Producing Economically Important Light
7. Manufacturing Photonic Integrated Circuits En Masse
8. 10G Networks Help Broadband Services Grow Faster than Moore's Law

1. INTERNET-BASED TELEVISION: MAKING IT PRACTICAL AND AFFORDABLE

Combine high-speed telecommunications networks with the flexible techniques for sending data over the Internet, and you get IPTV, or Internet Protocol Television, a newly emerging method for delivering digital video to homes. Rather than broadcasting hundreds of channels at a time to every subscriber's home, IPTV provides individual content on demand, by efficiently storing both live broadcasts and stored video on a provider-wide network. IPTV can also blend in voice, Internet, and other services onto a single TV screen, while offering portability to subscribers to access the television channels to which they subscribe, on different user devices and/or locations (e.g., on their laptops and even in their friend's homes). Researchers at the meeting will describe techniques for implementing IPTV at affordable costs while leveraging existing infrastructure.

Samrat Kulkarni and his fellow engineers at Lucent Technologies Bell Labs will present models and case studies for "transport networks" between a provider's regional office and individual subscribers. Such transport networks contain the hardware to deliver high-speed signals to the curb, while giving telecom providers the freedom to reuse their own infrastructure (even old-fashioned copper cable) to deliver IPTV the rest of the way to their subscribers' homes. The authors modeled Lucent's IPTV transport system in various trial scenarios. The scenarios involved real world situations in which Lucent worked with different telecommunications service providers (carriers) to support currently existing infrastructure, which utilize both old and new telecom technologies. The methods and examples explained by the authors suggest a superior system for existing and future customers that will bring a convenient and cost-effective solution to loyal carrier customers, while at the same time helping carriers to achieve greater service options, with expanded bandwidth and higher speeds, for whatever telecommunications needs and advances may arise in the future. (Paper NWC1, “Access Transport Network for IPTV Video Distribution”)

2. PINPOINTING STRUCTURAL PROBLEMS EARLIER WITH FIBER OPTICS

University of Ottawa physicists have demonstrated an optical system that detects problems in important structures, including natural-gas pipes and concrete columns, more precisely than before. Called the Distributed Brillouin Sensor (DBS), the system uses fiber optics to detect deformation, cracks, and bending in structures under real-world conditions. Already being considered for commercial production, the new system can catch much earlier signs of costly and dangerous structural failures than previously possible.

In one demonstration, conducted with civil engineers at the University of Ottawa, the researchers tested the DBS system on a concrete column encased with fiber-reinforced rods and sheets. Subjecting the column to simulated seismic forces such as those that would occur in an earthquake or tsunami, the researchers could detect signs of debonding (in which the concrete detached from the fiber casing) and the crushing of concrete as a result of compression forces. Unlike competing techniques, the system could readily tell the difference between debonding and crushing.

The Ottawa researchers say that DBS can prevent potentially life-threatening and environmentally damaging accidents and multimillion-dollar repairs. Unlike present structural health analysis, which is done on a spot-by-spot basis, DBS can detect problems over all points in the entire structure and pinpoint them to within 5 centimeters, while detecting mechanical strains as low as 20 microstrains, exceeding the 1-meter resolution and 50 microstrain levels that the construction industry has wanted and expected. In addition, the technique can improve the testing of structures and materials by providing valuable information during the testing process. (Paper OTuL7, "Distributed Brillouin Sensor Based on Brillouin Scattering for Structural Health Monitoring")

3. DELIVERING SUPER-BROADBAND WIRED AND WIRELESS SERVICES SIMULTANEOUSLY

Currently, telecommunications providers generally supply services that are either all-wireless (e.g. mobile phones) or all-wired (such as DSL and cable). If a customer wants wireless access from a cable modem, for example, he or she must purchase additional equipment.

Now, Gee-Kung Chang of the Georgia Institute of Technology and colleagues have designed and experimentally demonstrated a network that telecommunications providers could potentially use to simultaneously provide high-speed wired and wireless super broadband services with the same optical signal.

Using existing passive optical network (PON) infrastructure (which enables fiber-optics services to be delivered directly to homes) without the need for expensive electronic equipment, the design can simultaneously deliver broadband services such as high-definition television (HDTV) via an optical plug on a building wall and through a wireless network at a data rate of up to 2.5 Gigabits per second, significantly faster than the 100 Megabits per second in many current state-of-the-art Wi-Fi systems.

This hybrid technique can be incorporated into all-optical-fiber networks (also known as fiber-to-the-home, or FTTH networks) that telecom providers are currently deploying in business and residential areas. In their network system, the researchers first use standard techniques to “up-convert” a digitally modulated fiber-optic signal in the infrared range to one in the microwave or millimeter-wave range. This up-converted signal is split into two parts at the customer's premises, one that is detected by a high-speed receiver, then amplified before being transmitted as a wireless signal. The other part is sent directly to the plugs on a building wall via optical fibers. The key to this advance is the employment of low-cost optical receivers and amplifiers to provide the wired and wireless signals. Currently, the researchers are working with several service providers and equipment vendors to further develop their system into a product. (Paper OFM1, “Novel Optical-Wireless Access Network Architecture for Simultaneously Providing Broadband Wireless and Wired Services”)

4. E-SCIENCE: THE FUTURE OF SHARING DATA

Advances in high performance networks are enabling new frontiers of discovery. Large-scale research, often referred to as e-science, typically involves collaborative teams of scientists and scientific equipment located around the world. National governments and research organizations are investing in multimillion-dollar technical instruments (such as high-voltage electron microscopes) and facilities to collect vast amounts of raw data. However, numerous steps are involved, such as time-consuming person-to-person data queries, before information can be visualized and analyzed by joint research teams situated across countries or across multiple continents. What if particle physics data from the Large Hadron Collider, at CERN near Geneva, Switzerland, could be made available to researchers in Chicago, Bombay or Tokyo in real-time?

Gigi Karmous-Edwards of MCNC in Research Triangle Park, NC, envisions easily connecting researchers to remote data through new optical-fiber network configurations. Network-transport protocols and dynamic optical network configurations will be as essential as high-performance computing resources in order to solve complex scientific problems. She works as part of the Global Lambda Integrated Facility, an international community that supports data-intensive scientific research and helps develop middleware to coordinate the resources that e-science requires. Her talk will discuss some of the optical networking challenges that need to be solved as global e-science collaboration evolves. (Paper OWU3, Today's Optical Network Research Infrastructures for E-Science Applications)

5. THINKING INSIDE THE BOX: SQUARE-CORE FIBER PROMISES FASTER, MORE EFFICIENT MANUFACTURE OF FLAT-PANEL DISPLAYS

John Hayes of the University of Southampton and his colleagues have designed, built and tested a new fiber with a square-shaped core rather than the traditional circle-shaped cross section. The square-core fiber may lead to faster, more cost-effective and more energy-efficient production of flat-panel display screens. The fiber may also be useful in medical procedures, device manufacturing and other industrial processes involving laser light.

In the manufacture of flat-panel displays, one can use lasers to remove, or ablate, rectangular-shaped regions from an electrically conducting coating (typically indium tin oxide, or ITO) on a glass screen. The ITO regions that remain form the electrodes for the RGB sub pixels. Presently, these electrodes are formed by expensive lithographic processes involving resist coating, exposure, developing and etching steps. It is possible to replace this multi-step complex process by a single-step laser-based technique. Current technology utilizes circular-core beams which are passed through a series of expensive, complicated optics to make a square-shaped beam. The overall efficiency of such a system is quite low such that high power lasers are required. In contrast, the square-core fiber can directly deliver an intense square shaped beam of light to make the electrodes much more efficiently.

This new fiber is a type of microstructured or “holey” fiber. Holey fibers have tiny holes running through them in a pattern that trap light in a solid core. In this carefully constructed fiber the holes are arranged in a square producing a very neat square beam of light.

According to Hayes, the fiber can accept a wide variety of input beams but provides a uniform, square beam at the output end making it immediately useful in the manufacture of flat panel displays. This novel fiber design, with its well defined core geometry, extends the capabilities and precision of light manipulation in manufacturing and other fields. (Paper OThH3, “Square Core Jacketed Air-Clad Fiber”)

6. PRODUCING LIGHT IN AN ECONOMICALLY IMPORTANT REGION

Bismuth-doped fiber lasers can produce light nicely in the economically important wavelength region around 1.3 microns. This spectral region is sometimes referred to as a “second window” (the first being around 0.85 microns and a third at 1.55 microns) for data transmission since optical loss for light at 1.3 microns is only about 0.35 decibel per km and chromatic dispersion in silica-based glass is nearly zero. Research with fiber lasers in this region, however, has encountered some physical and technical obstacles. Consequently, there have been no effective silica-based fiber lasers and amplifiers at 1.3 microns.

This changes now, with the work of E.M. Dianov of the Fiber Optics Research Center at the A.M. Prokhorov General Physics Institute of the Russian Academy of Sciences and his colleagues. At the meeting, they will report the first bismuth-doped silica fiber laser, with up to 0.5 watts of power in the spectral range 1146-1300 microns. (Paper OTuH4, “Bi-Doped Silica Fibers: A New Active Medium for Tunable Fiber Lasers and Broadband Fiber Amplifiers”)

7. MASS-PRODUCING PHOTONIC INTEGRATED CIRCUITS

Photonic chips, the opto-electronic equivalent of electronic microchips, often come in pairs, one for transmitting photonic signals and one for receiving. At the meeting, Fred Kish of Infinera Corporation, will report that his company can manufacture integrated photonic chips in great volume. The overall data rate for these devices is 100 Gb/sec. The sending chip contains 10 lasers, 10 modulators (each capable of working at 10Gb/sec rates for a total rate of 100 Gb/s), a demultiplexer, and other devices, while the receiving chip contains complementary devices, such as photoreceivers, multiplexers, etc. This is in comparison with typical present industry performance data rates for long-haul telecom systems of 10 Gb/sec per chip; a few can go as high as 40 Gb/sec. (Paper OWL1, Kish et al., “Volume Manufacturing and Deployment of Large-Scale Photonic Integrated Circuits”)

8. 10G NETWORKS HELP BROADBAND SERVICES GROW FASTER THAN MOORE'S LAW

Bob Harris of Time Warner Cable will discuss the architecture of large-scale fiber-optics-based 10G networks able to deliver such services as voice, video, and Internet service to regional, community, and government customers. High-bandwidth networks operating with multiple optical channels, where each channel is 10G-enabled, Harris says, offers compelling economics in the delivery of services across local, metropolitan, and regional networks. Providers are now able to offer new services and support the rising traffic demands that are increasing at a rate greater than Moore's law (i.e., more than doubling every 18 months). In addition to helping proliferate services such as VoIP (Internet telephone), 10G networks facilitate the economic delivery of telecom services to government organizations such as broadband access to K-12 grade students. Harris will point out the technological aspects of these networks that make them so powerful and flexible. For example, they transmit up to 40 wavelengths of light simultaneously through fiber lines, unlike previous generations, which would only transmit several wavelengths or less. In addition, crucial elements of a 10G system, such as routing and switching, are located at the edges of the network, rather than at its center, analogous to how the workers of many cities reside in the suburbs, rather than in the midst of a metropolis. Multi-wavelength 10G networks build upon previous generations of network systems and fiber-optics technology. The open-ended architecture of 10G, Harris says, provides the ability to keep up with bandwidth demands and deliver new broadband services as they become available, helping people become better connected than ever before. (Paper OTuJ1, “10G-Enabled Optical Network Architecture Directions for Video, Voice and Data: An MSO Perspective”)

A press room will be located in the Anaheim Convention Center, room 208A. The press room will be open Sun., Mar. 5, 12 p.m. - 4 p.m. and Mon., Mar. 6 - Thurs., Mar. 9, 7:30 a.m. - 6 p.m. Those interested in obtaining a badge for the press room should contact OSA's Colleen Morrison at 202.416.1437, [email protected] or Melissa Norr, 202.416.1443, [email protected]. More information can be found online at http://www.ofcconference.org/media_center/ , including exhibitor press releases and other materials.

About OFC/NFOEC:
Since 1985, the Optical Fiber Communication Conference and Exposition (OFC) has provided an annual backdrop for the optical communications field to network and share research and innovations. In 2004, OFC joined forces with the National Fiber Optic Engineers Conference (NFOEC) creating the largest and most comprehensive international event for optical communications. By combining an exposition of more than 600 companies, with a unique program of peer-reviewed technical programming and special focused educational sessions, OFC/NFOEC provides an unparalleled opportunity reaching every audience from service providers to optical equipment manufacturers and beyond.

OFC/NFOEC, http://www.ofcnfoec.org , is managed by the Optical Society of America (OSA) and co-sponsored by OSA, the Institute of Electrical and Electronics Engineers/Communications Society (IEEE/ComSoc) and the Institute of Electrical and Electronics Engineers/Lasers and Electro-Optics Society (IEEE/LEOS). Acting as a non-financial technical co-sponsor is Telcordia Technologies, Inc.

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