AF-Funded Engineer Honored for a Lifetime of Scientific Achievements

  • Published
  • By Molly Lachance
  • Air Force Office of Scientific Research
Arlington, Va. --  After decades of research at the University of Michigan in areas ranging from materials to circuits, 2008 has been an especially noteworthy year for Dr. Pallab Bhattacharya, who earned numerous accolades from the engineering community.

This year three well-known organizations recognized Dr. Bhattacharya for his significant achievements. The National Academy of Engineering (NAE) elected him as a member; the Institute of Electrical and Electronics Engineers Nanotechnology Council co-awarded him the first ever Pioneer Award in nanotechnology; and The Minerals, Metals and Materials Society chose him as the 2008 John Bardeen Award recipient.

These awards and recognitions have come as a result of Dr. Bhattacharya's important impact on optoelectronics and nanophotonics. His work with quantum dots has improved laser, optical communication and long-wavelength detector technologies.

Quantum dots are very small, self-organized islands of semiconductors that behave like artificial atoms, explains Dr. Bhattacharya. One big difference, however, is how they behave when injected with electrons and holes, collectively referred to as charge carriers.

After dedicating considerable effort to understanding the dynamics of these injected charge carriers, Dr. Bhattacharya was ultimately able to use quantum dots to create a new type of laser that combined the best qualities from semiconductor lasers and atomic lasers.

"A decade ago, we were the only group in the world looking at the initial deficiencies of high-speed quantum dot lasers," said Bhattacharya. "We solved the problems and now they are awesome devices."

As he and his team learned more about the pros and cons of using quantum dots in laser technology, they found that some of the deficiencies in laser applications are advantages for long-wavelength detectors. One such advantage is the ability to use the detectors at much higher temperatures.

A current project funded by the Air Force Office of Scientific Research (AFOSR) has extended this research to terahertz-frequency wavelength detectors. The Air Force plans to use these devices, which measure very long wavelengths, for multi-spectral detection in airborne and terrestrial settings.

In another AFOSR-funded project, Dr. Bhattacharya is exploring the possibility of growing quantum dot lasers directly on silicon, allowing scientists to use light instead of charge to route information on chips. This would eliminate the need for metal interconnects, which generally have problems with heating, electromigration and propagation delays.

Over the next several years, Dr. Bhattacharya will continue his research, focusing primarily on silicon light sources and nanolasers with total dimensions no larger than their wavelengths.

For a man with so many other achievements, Dr. Bhattacharya has expressed genuine excitement about his recent success. He is looking forward to the NAE induction ceremony scheduled for October 5, 2008 in Washington, D.C., which he describes as the "big event."

While each award is meaningful to Dr. Bhattacharya, he is particularly grateful for his nomination and election as a member of the NAE, a selective group of only about 2,000 members and one of the highest professional honors accorded an engineer. Dr. Bhattacharya said that after learning he would receive this prestigious honor, all he could do was sit down and let it sink in.