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At Lehigh University, the Center for Optical Technologies advances the fields of fiber optics and photonics with an eye on spurring economic development

By Tom Gibson

Walking along trying to find my way on the campus of Lehigh University in Bethlehem, Pennsylvania, I stop at a directory board with a campus map. A lady then walks up and asks where I’m going. When I say Sinclair Lab, she replies,”You can’t get there from here because of the construction going on.” Indeed, earthmovers were busy digging a huge hole for the foundation of a new building next to Sinclair Lab on the venerable Lehigh campus with its old, gothic stone buildings gracefully adorning a wooded hillside.

I learned later this was going to be a new lab building for the Center for Optical Technologies (COT), one that symbolizes the bright future for this expanding high tech center. COT aims to advance research and applications of optical and optoelectronic technologies, and though it takes the usual shape of a research center in an academic setting, it has an added twist. Director Tom Koch says, “Our charter involves three things: new science, educating people, and economic development.”

Lehigh launched COT in 2001 with an initial seed grant of $1 million followed in 2002 with a five-year $15 million grant from the Pennsylvania Department of Community and Economic Development. The university is matching the state grant, and since 2002, COT has secured more than $5 million of funding from the U.S. Department of Defense for collaborative optics research programs.

In doing this, Lehigh is partnering with Penn State University, Northampton Community College and Lehigh Carbon Community College nearby, and Ben Franklin Technology Partners of Northeastern Pennsylvania. They also have an industrial membership program to provide local and national companies access to COT research, facilities, and business development opportunities. Ten companies have come on board with names like TriQuint Semiconductor, Corning, GlucoLight, infinera, T-Networks, IQE, and ASIP.

As Kim Trapp, industry liaison officer points out, “Optics is a broad field. It touches almost everything in our everyday lives.” This translates to an interdisciplinary approach when it comes to researching it. Some 60 faculty members and researchers from Lehigh and over 20 from Penn State have joined COT from electrical & computer engineering, physics, chemistry, bioengineering, materials engineering, mechanical engineering, and chemical engineering disciplines.

Tom Koch and Kim Trapp both came to COT in 2003 -- actually by coincidence, they point out -- after working together in the fiber optics industry for many years. Both worked several years for Bell Labs’ research center in New Jersey. Koch later became vice president for technology platforms at Agere Systems, a spinoff from Lucent Technologies. He earned his bachelor’s degree in physics from Princeton and doctorate in applied physics from the California Institute of Technology. At Lehigh, he also serves as a professor of electrical and computer engineering. Trapp previously served as marketing operations director at Agere Systems. With a B.S. from Purdue in chemistry and a master’s in inorganic chemistry from Fairleigh Dickinson, she managed Lucent Technologies’ optoelectronics telecommunications product portfolio before that.

A University Hub in a High-Tech Area
An obvious first question you have to ask is why put COT at Lehigh University in the Lehigh Valley of southeastern Pennsylvania? Koch responds, “A lot of it was borne out of the rapid growth in telecommunications, going back to 1999 and 2000. As opportunities grew in that area, engineers like us would get a bee in their bonnet to start a company and compete with Lucent Technologies or follow up some new opportunity.” As a result, many startup technology companies cropped up in the area. “People had a vision of this being a big bustling part of the economy around here, and they saw a void in it.” Koch explains that most high tech regions have a university as an anchor; Silicon Valley in California has Stanford and Cal Berkeley, while Boston has MIT around its technology corridor. “Here, they didn’t have a university hub geographically approximate to this area.”

Lehigh, with its prestigious engineering school, made an obvious choice. As Trapp says, “All the disciplines are here at Lehigh to do this optics work. We have the largest microscopy facility in the country. Materials science and microscopy are Lehigh’s strengths.” They’re also big in electrical engineering.

But in 2001 and 2002, the telecommunications industry collapsed. Many companies went under, and those still alive have laid off most of their R&D staff. In a couple of ironic ways, though, this actually set the stage for COT to evolve. For starters, the center purchased some $200 million worth of equipment from companies that folded. Koch says during boom times, companies had enough resources that they didn’t need universities for doing research. “The role we play now in coupling with them is much more traditional. It’s doing the higher-risk, deeper science they don’t have the capability to do. The downturn has made some of our coupling more meaningful to companies that don’t have the resources.”

In simple terms, fiber optics involves converting an electrical signal to an optical signal and transmitting it through a glass fiber. All computers, phones, and communications systems start out generating electrical signals. Engineers have devised microchips that convert a current pulse into a light pulse using a laser. These encode the light onto a fiber at one end, and at the other end, they do just the opposite, detecting the light and turning it into electricity. Using fiber optics for signal transmission has proven far superior to sending electrons through copper cables because data can be sent in enormous volumes and at much greater speeds. A fiber optic line can carry 150,000 voice conversations.

To get a hands-on feel for fiber optics, I ventured into a lab at COT manned by Mark Webster and James Dailey. Webster has a Ph.D. in electrical and computer engineering from Purdue and master’s and bachelor’s degrees from the Royal Melbourne Institute of Technology in Australia with a specialty in optics. As a post-doctoral research associate, he researches, designs, fabricates, and characterizes silicon-based photonic devices with Dailey assisting him as a Ph.D student in electrical engineering. They showed me a small device that generates a light beam and outputs it through a fiber (the beam was infrared, so a human eye couldn’t see it). It fed to an oscilloscope, which plotted a sinusoidal graph of the signal.

Optical fibers are hair-thin, and Webster explains they’re made from silica, like regular glass. Coated with a polymer and wrapped in plastic sheaths for protection, a thin fiber of glass is flexible, almost like a wire. Webster explains how fibers are made by starting with a glass rod about an inch in diameter and two feet long and drawing it by continuously applying a vertical tensile load with a weight in a fiber drawing tower. A typical long-haul transmission cable may have from a dozen to hundreds of fibers in it. They follow existing corridors such as highways, railroads, power lines, and gas lines, being buried underground, and for local distribution, they sometimes run on telephone poles. Fiber optic lines serve as a means of communication between continents in the form of large transatlantic cables.

Becoming Commonplace
According to Koch, “We transitioned from being mostly voice on these networks to mostly data about three years ago,” due mostly to the growth of the Internet. Fiber optic transmission lines have replaced electrical lines in almost all long-distance connections. Virtually all traffic flows over fiber optics, then when it gets close to its destination, it typically gets converted to an electrical signal, usually at a local office serving a town, from where it gets distributed to homes on electrical wires.

Meanwhile, lightwave systems have evolved through several developmental stages, and the capacity has steadily increased exponentially over the years by about a factor of ten every three years. Today, commercial systems transport data at hundreds of gigabytes per second over thousands of kilometers, simultaneously transmitting of 100 to 150 channels in a single optical fiber.

But experts say we’re approaching ultimate capacity in transmission lines, and therefore research is gradually shifting to the systems used with the transmission lines and the networks extending from the lines to the internal workings of communications devices. Currently the two primary research focus areas at COT are optical networking technologies and sensor and display technologies.

In typical systems, several of the functions that must be performed in the network still require the conversion of optical signals to electronic and back to optical. One such function is the regeneration of a signal approximately every 80 kilometers along a transmission fiber, as a light beam degenerates. With hybrid optic/electronic repeaters, optical signals are detected and converted to electronic signals, amplified, retimed, and reconverted back to optical signals to be sent forward along the system.

Researchers are exploring ways to do that without using any electronics because, as Webster says, “All-optical conversion of signals is quicker. Electrical signaling is slow. Optical switching can be done hundreds of billions of times a second.” This will require new components, subsystems, and materials.

Photonics Yields Semiconductor-Like Chips
As a result of this research, the field of photonics has evolved, which involves combining optical and electrical components on a silicon chip. It may have several optical waveguides, actually air holes that act as a signal conduit like a fiber. A chip would go inside a computer, as one example, and a fiber may output from it. Webster says they use standard semiconductor techniques in fabricating such chips.

On the materials side, COT is developing materials with enhanced optical properties such as higher index, lower loss or higher gain, stronger emission, and wider bandwidth. New materials include glasses made with materials such as telluride and chalcogenides. Telluride fibers are doped with rare earth elements such as erbium. COT is also investigating glass-ferroelectric nanocomposites made from ceramic material.

With all these advances, though, Koch points out another area that must be addressed. “People will have to come up with much better ways of making chips, much better ways of putting them into modules.” Extensive mechanical engineering goes into aligning a thin light beam coming out of a box into a fiber. “The problem is, today you can’t do that cheaply.” The industry has improved from a person using a microscope to using robots. “There’s still a million-dollar robot sitting there moving chips around and aligning them inside gold boxes and then freezing them in place with big laser welding systems.”

It becomes obvious many players are involved in the fiber optics world, and many parties can benefit from it. “We’re trying to emphasize the partnership concept. A lot of the funding comes from the state of Pennsylvania, and their motive in trying to get this to happen is economic development,” Koch says. “We’re trying to broaden our picture to make it not just the people down the street.” COT deals with national companies, hoping they’ll set up or fund some activity in the area such as research that will lead to jobs or a branch office to incubate new concepts.

Some of COT’s member companies contribute funds, so they can gain access to facilities at Lehigh or participate in joint research or development activities. And companies get to know Lehigh engineering students, so they can hire them when they graduate.

As I leave Sinclair Memorial Laboratory, I look over toward Harvey Neville Hall and eye the new foundation construction crews are digging for COT’s new building, which will have 3000 square feet and three stories. Eventually, it will house an optoelectronics clean room and big reactors for growing optical material, giving Lehigh capabilities in device growth, processing, and fabrication and providing a final piece of the puzzle. As Trapp says, “We’ll be able to do the whole process then. That’s exciting.” With such an addition to the fiber optics landscape, COT has an exciting future ahead of it.

For more information, visit www.lehigh.edu/optics

Two Companies That Have Benefited from Working with the Center for Optical Technologies

Infinera
In the past, the Center for Optical Technologies and others have researched an all-optical network and the elimination of costly optical-electrical conversions in optical networks. But Infinera has taken what it calls a contrarian approach.

Since eliminating electronics eliminates digital capabilities, all-optical also means all-analog. As an optical system becomes more analog, it becomes more complex, more sensitive to noise and impairments, less flexible, and more difficult to engineer and manage.

Infinera has developed the first large-scale photonic integrated circuits (PICs), which make a digital optical network possible by providing order-of-magnitude cost reduction for optical-electrical-optical conversions. The company makes turnkey communications systems for major telecommunications carriers.

A large company based in Sunnyvale, California, Infinera has other U.S. offices in Allentown, Pennsylvania and Baltimore, Maryland and a subsidiary in India. Some 25 people staff the Allentown facility, where they do mechanical, optical, and thermal design of PIC modules. They also develop manufacturing, assembly, and test processes and conduct life testing. And they manufacture the modules, assembling components in hermetically sealed boxes.

Michael Reffle serves as general manager at the Allentown facility, with an undergraduate degree in electrical engineering from Drexel and a master’s in engineering management from the University of Dayton. He says COT has assisted his group in a number of ways. They have consulted Lehigh’s professors on material science and metallurgy issues, and they’ve also used some of the center’s analytical equipment. But most notably, “We’ve used several of the professors to discuss our next generation product.” COT has assisted them in creating a large database of manufacturing test data. “We’re doing extremely well with customers. From that perspective, they’ve helped keep us on a very aggressive schedule.”

Reffle continues, “The collaboration between us and Ben Franklin and the center has allowed us to accelerate our next generation development.” He says it will eventually help with product time to market. “It will be a great advantage to us. We’re grateful to be this close to interact with those guys.”

For more information, visit www.infinera.com

GlucoLight
Jeff Shakespeare began working for COT in 2003 as a visiting research scientist. A couple months after he started, two guys came in that had recently founded a company to build an optical non-invasive glucose monitor for diabetics. They had licensed technology developed at the University of Texas medical branch.

His interest piqued, Shakespeare joined the entrepreneurs in the venture known as GlucoLight Corporation, currently supported by the Ben Franklin Technology Partners in a business incubator on Lehigh University’s Mountaintop Campus. He splits his time between COT and the fledgling company. Shakespeare has Ph.D., M.S., and B.S. degrees in mechanical engineering, all from Lehigh, and extensive experience in the telecommunications and optoelectronics industries.

“The medical people had done good work in developing the system and getting patents on it, but it needed to be made into a product. It needed people who understand the packaging, automated manufacturing, optics, and those are all my strong suits,” Shakespeare recalls. “It was a startup. We had no money, no office, no nothing. Tom Koch (director of COT) was gracious enough to let us use his lab and some of the equipment. We actually set up in the lab and began our first experiments with the technology in Tom’s lab.” They were there for six months before moving to the incubator. “The center was a huge jumpstart for us.”

An optical glucose sensor uses a principle called optical coherence tomography. Light enters the skin from the device, and the amount of light scattered back varies with the amount of glucose in the fluid surrounding the cells. A photodetector picks up light bouncing back. At COT, GlucoLight used instruments to measure light wavelengths and power levels and set their device up on an optical table.

"Our technology at GlucoLight is working a lot better than even I expected," Shakespeare reports. They have their first-generation prototype under test at Lehigh Valley Hospital in Bethlehem. "We’ve done 15 healthy patients and 16 diabetic patients, and the results have been outstanding."

Progressive Engineer
Editor: Tom Gibson
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©2004 Progressive Engineer