Air Force Funds Laser Source Technology for UAVs

  • Published
  • By Maria Callier
  • Air Force Office of Scientific Research
Arlington, Va. --  An Air Force-funded Multidisciplinary University Research Initiative (MURI) program is examining the use of lasers to remotely probe and identify the exhaust from aircraft such as unmanned aerial vehicles (UAVs) and track chemical smoke plumes without harm.

The research is being conducted at the University of Wisconsin, under Dr. Daniel van der Weide, professor of Electrical & Computer Engineering.

"The techniques we are developing will be of direct benefit to sensing requirements for aircraft such as UAVs," said van der Weide who has collaborated with his co-researchers to develop instruments that can measure the complete infrared and terahertz electric field.

"These instruments are collectively called frequency comb spectrometers because their short pulses have correspondingly broad spectral content, and because they emit repetitive pulses that look like teeth in a comb," said van der Weide.

Professor van der Weide and his team use ultra-short pulse lasers to generate the combs, then they convert the near-infrared lasers into far-infrared or terahertz signals, depending on the application.

"One laser provides the signal for testing, and one is used to probe the test signal, giving output that may be transformed to provide the full electric field information at hundreds of frequencies, all at once," said van der Weide.

Scientists have recognized these research techniques around the world and in many laboratories the methods are being rapidly developed.

The scientists' most challenging problem is that they need to reduce the size of the lasers that generate and measure the full field (magnitude and phase) signals. Professor van der Weide and his team are addressing the challenges with the support of AFOSR Program Manager, Dr. Gernot Pomrenke through a Small Business Tech Transfer program that enables them to work with an advanced supplier of fiber lasers, Polaronyx.

The program recently gained wider attention in academia because a paper about the magnitude and phase field measurements used for stealth applications was featured in the "Best of 2008" collection of articles in the New Journal of Physics. The Editorial Board and publishing team selected van der Weide's article, "Vector Frequency-Comb Fourier-Transform Spectroscopy for Characterizing Metamaterials" because it best represents the "diversity, originality and quality of papers."

Professor van der Weide and his team are continuing their research on laser source technology, as well as remote field measurements, which is of particular relevance to accurately measuring the Air Force's high-power, high-frequency antennas.