Optical fiber breakthroughs to be announced

Bandwidth on demand, switchable photonic crystals, multicolored laser light

Speakers will present some of the newest and most interesting topics in the science of fiber optics at a press conference to take place at the 2003 Optical Fiber Communication Conference and Exhibit (OFC 2003) in Atlanta, Georgia.

The news conference will convene Wednesday, March 26 from 10AM to 11:30AM in Room C104 of the Georgia World Congress Center. Reporters wishing to attend should fill out the reply form at the end of this release, or contact Colleen Morrison (202-416-1437, [email protected]) or James Riordon (301-209-3088, [email protected]).

OFC 2003 NEWS CONFERENCE
Room C104
Georgia World Conference Center
Wednesday, March 26
10:00 AM - 11:30 AM

SPEAKERS AND TOPICS:

BANDWIDTH ON DEMAND
Ronald Skoog
Telecordia Technologies

As anyone who has priced Internet service providers knows, higher bandwidth (i.e. faster connection speed) costs more. To make matters worse, high bandwidth may be wasted when high-speed connections are used for low-bandwidth applications, such as sending email. Ideally customers, and particularly large companies, would save money by paying only for the bandwidth they need at any given time, rather than paying premium rates for the high bandwidth that they only require on occasion. Ronald Skoog will ponder the fundamental forces that will drive future deployment of Bandwidth on Demand (BoD) services and the network design that will make them work. He will also explore how dynamic, flexible networking capabilities will most likely be used, what type of services will ultimately be available to BoD customers, and how this will change the industry.

INCREASING TELECOMMUNICATIONS CAPACITY WITH POLARIZATION
Neal S. Bergano
Tyco Telecommunications

To maximize the data capacity of fiber-optics lines, modern systems send multiple colors of light down an optical cable, with each color representing a "channel" that carries different data. To increase transmission capacity even further, one can add channels by using more colors within the existing spectrum of light. This is analogous to putting more radio stations on the same dial. But when one squeezes in more colors, there is a greater risk of "crosstalk" or interference between the channels. A few years ago, Neal S. Bergano and Carl Davidson of Tyco Telecommunications invented a technique to reduce this crosstalk by giving adjacent channels orthogonal polarization, in which the electric field directions of the light waves associated with adjacent colors are perpendicular to one another. To achieve the ultimate in tight channel spacing using the orthogonal launch technique one needs to add the additional step of polarization tracking at the receiver, where the incoming electric field direction of a degrading signal is converted to a desired electric field direction. Bergano will discuss the first demonstration of the technique, which was accomplished by sending, over a distance of 6,500 kilometers, 10 Gigabits of data per second in each channel with a spacing of 15 Gigahertz in frequency (0.12 nanometer wavelength) between the colors in neighboring channels. The demonstration led to a record 66% level in an important quantity called "spectral efficiency," which represents the bit rate per channel divided by the channel spacing.

SWITCHABLE PHOTONIC CRYSTALS
Jun Qi
Brown University

Photonic crystals can affect the flow of photons in much the same way that electronic devices control the flow of electrons. Most photonic crystals, however, have specific properties that cannot be varied once the crystals are made. A few types of photonic crystals, such as fluid suspensions of colloidal silica, can be modified on the fly, but the time required to switch configurations is inconveniently long. Researchers at Brown University have now made photonic crystals that can be modified in fractions of a second. The switchable photonic crystals consist of a class of material known as holographic-polymer dispersed liquid crystals (H-PDLCs). Structures are defined in the material by exposing it to an interference pattern produced by a set of four laser beams. Unlike many other types of photonic crystals, the H-PDLC crystals can be modified in a single step. In addition, the new photonic crystals are easily constructed on a wide range of scales, and can replicate sophisticated structures including diamond lattices as well as anisotropic lattices that affect light differently depending on the direction it propagates through the crystal. Jun Qi will discuss switchable H-PDLC photonic crystals, which are the subject of two talks in the scientific OFC sessions.

MULTICOLORED LASER LIGHT
Akheelesh Abeeluck and Jeff Nicholson
OFS

When college professors and business executives brandish their laser pointers, they are inadvertently showing off the unique qualities of laser light. For example, lasers basically produce a single pure color, such as red, in stark contrast to lightbulbs, which shine many colors that mix together to make white. But now, researchers are combining lasers and fiber optics to generate multicolored light sources. Launching intense laser light into a specially designed optical fiber generates "nonlinear" effects that convert single-colored light into a wide range of colors. The resulting "supercontinuum light" has all of laser light's benefits but many additional uses. For example, it could allow a single laser to generate the multiple colors of light that travel down fiber in modern transmission systems, such as WDM. It could serve as a basis for ultra-precise "optical" clocks that promise better global navigation. It could provide light with very broad bandwidths for a medical imaging technique known as "optical coherence tomography" which can yield detailed images of human tissue. In the past year, there has been a flurry of new techniques for producing supercontinuum light. Jeff Nicholson will describe the production of the broadest spectrum of supercontinuum light ever achieved in a desirable design known as a mode-locked erbium-doped fiber laser; Akheelesh Abeeluck will discuss the broadest spectrum of continuous-wave supercontinuum light ever generated with a Raman fiber laser.

NEWS CONFERENCE REPLY FORM
OFC 2003
March 26, 2003
10:00 a.m.
Room C104, Georgia World Congress Center
Please return this form to James Riordon at [email protected] or by fax at 301-209-0846

___Please sign me up for the OFC news conference.

___Please send me the general press release for the meeting.

___I cannot attend but please send me additional materials as they become available.

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For more information please contact James Riordon, American Institute of Physics, [email protected], 301-209-3084 Also see the OFC website at http://www.ofcconference.org/