Electrical and computer engineers improving FSO technology

Of the many groundbreaking projects underway in TU’s J. Newton Rayzor Hall, one aims to transfer data through the transmission of light through air. Known as optical wireless or free space optics (FSO), TU’s research on this method of communication has been funded by the National Science Foundation for the past seven years. Professor Peter LoPresti in the Department of Electrical and Computer Engineering currently is developing an optical transceiver design that will establish a rapid optical link/network among multiple unmanned aerial vehicles and support multi-user communication.

Optics lab research
Students beam a laser through a heated box to test its response to turbulence.

“The goal is to develop a very secure, very high bandwidth form of communication that is mobile,” he said. “Optical transmission is the ideal technology because lasers transmit very directionally, and the signal is difficult to intercept.”

A small group of electrical engineering and electrical and computer engineering graduate students are involved in the project, and undergraduates have contributed through the Tulsa Undergraduate Research Challenge (TURC). The research is conducted in Rayzor Hall’s Optics Lab where a floor independent from the building’s concrete slab prevents the slightest vibrations from disturbing experiments involving sensitive equipment.

According to LoPresti, the heightened FSO technology potentially could improve critical applications such as disaster area wireless communications. Corporations and federal organizations including the Department of Defense and NASA have shown interest in TU’s developments.

“Technological advancements over the past 15 years are positioning unmanned aerial systems to play a pivotal role in civilian and military domains,” he said.

The network involves four areas of focus — algorithms for implementing an all-optical system; a transmitter with enhanced capabilities; a receiver than can provide a wider field of view and separate optical transmissions from at least three unmanned mobile devices; and a geometrical model that aids in controlling platform stability, design of the optical array shape and distribution of the network nodes.

“We’re trying to find solutions for two problems that impede development of a viable mobile FSO system: transceivers that support multi-point mobile connections and the ability to sustain connectivity within the dynamic environment of a rotor-based aerial platform,” LoPresti said.

Simulating turbulence through the application of a heated box, TU researchers are studying how the laser light of FSO technology is affected by turbulence in air. Today’s optical equipment uses multiple receivers pointed at each other to transmit a signal, but LoPresti’s research intends to employ only one unit that can transfer several different communications simultaneously on different light waves.

“We want one optical receiver to detect two or three signals just like a radio receiver,” he said. “We’re trying to develop multiple lines of communication that talk to each other. The math and our initial experiments say it can be done.”

LoPresti is in the process of obtaining another round of funding to continue the FSO research. He plans to include at least three TURC students in the project this summer.

Peter LoPresti