ŷ���ڱ���Ƶ

John Hall, a University of ŷ���ڱ���Ƶ Nobel Prize laureate and member of the Joint Institute for Laboratory Astrophysics, has won a 2010 Governor’s Award for High-Impact Research.

In a ceremony in October, Hall accepted the Foundational Technology award for exploration of the nature of the laser light, leading to the development of the laser as a tool for ultra-precise measurements, guiding its commercialization and nurturing of the phototonics industry.

As the award’s citation noted, Hall has led teams of researchers since the 1960s to explore the nature of laser light. His teams ultimately developed the laser as a tool for ultra-precise measurements.

The subsequent development of “laser frequency combs” utilizing multiple lasers has led to breakthroughs in telecommunications, medical research, semiconductor processing and photonics and contributed to numerous spin-off companies. Hall was awarded the Nobel Prize for Physics in 2005 in recognition of these discoveries.

“I was astonished and very pleased to learn that the work of our JILA team had been selected for the Governor’s Award for High Impact Research,” Hall said.

The early laser pioneers in the 1960s could see the potential that lasers would bring to measurement science, and with that, human access to probing into how nature works, he said. By the 1970s, JILA scientists had begun to make lasers much more stable, and by the mid 90s vastly more stable.

“Basically, we had an optical frequency source with the same kinds of stability specifications as the best electronic sources. However … we didn’t have any simple and accurate way to measure the laser frequencies in terms of the electronic standards—there was a frequency ratio of some 100,000:1 and we only had tools for jumping 2:1 at a time,” Hall continued.

The first experiments, in collaboration with colleagues at what was then called the National Bureau of Standards, did this jump 12 times in sequence, each step with different laser systems and technologies.

“Those frequency connections only increased the dreams for a better way,” Hall said. “My colleague in Munich, Professor Ted Haensch, has always been a great dreamer, and 1996 he saw how a mathematical connection could be accomplished between the disparate domains of optics and radio-electronics. But there were absolutely no tools or implementation ideas.”

Meanwhile, laser technology was improving, Hall added. For example, over the years laser-pulse repetition rates had reached 100 million pulses per second, and the pulses were vastly sharper in time.

Other people were interested in the nonlinear interactions that lasers can produce, most dramatically as the conversion of a nearly invisible red laser beam into a whole rainbow of color components.

“Our JILA group developed into one of the world leadership labs for making lasers have stable frequencies,” Hall said. “I happened to hear a post-deadline talk in a 1999 international conference and, upon realizing this was the missing link, became abruptly launched into the most exciting time of my life.

“While we couldn’t arrange an official collaboration with the labs that had this remarkable ‘Rainbow’ optical fiber, we eventually did come to have the use of some inches of this incredible nonlinear material,” Hall said.

“So in the last days of the last millennium it was possible for our JILA team to put all the components together for the first time, so that a laser with a repeatable pulse emission could be transformed into perhaps a million discrete optical frequencies—creating a whole rainbow of ultra-precise frequencies, effectively just like a million stable lasers, forming an Optical Comb. This breakthrough publication in 2000 brought a certain amount of attention worldwide and has led to too much travel for my wife, Lindy, and me.”

Meantime, Hall’s JILA/NIST colleague Jun Ye found several applications for this new technology, from synchronizing pulse lasers so that more accurate chemical probing would be possible, to using the technology for synchronizing sources at two separated locations. “This is being applied now for the large telescope array under construction in Chile, as well as at the accelerator at CERN,” the massive underground particle-accelerator in Switzerland.

“The optical comb can do simultaneous measurement at something like 1 million separate frequencies, which is ideal for isolating and measuring a gaseous sample containing many kinds of molecules,” he added.

The optical comb can be sensitive enough so that if the gas were a person’s exhaled breath, “we have basically a new and powerful instrument for studying human metabolism and, especially, departures from normal.”

The high sensitivity allows for the detection of many molecules that are known to be markers for diseases, including asthma, liver failure, lung cancer and diabetes, Hall said. Practical diagnostic instruments are being developed.

Another application of the optical comb is in calibrating astronomical spectroscopes, an enabling tool in searching for Earth-like exoplanets on the basis of their gravitational tugging on their local ‘sun,’ thus causing minute Doppler shifts in its spectral lines, Hall said.

“Dr. Ye’s group has also learned how to store up a few hundred of these mega-pulses emitted by the mode-locked laser, and this way the energy of the individual packets can be coherently added, increasing the power level several-hundred-fold and enabling a next generation of study into highly nonlinear processes,” Hall concluded.

“I take great pride that this highly creative team for applications is under the direction of my former Ph.D. student, Dr. Jun Ye! The research circle just goes on!”

The Governor’s Awards for High-Impact Research are bestowed in cooperation with, CO-LרS, a non-profit consortium that educates ŷ���ڱ���Ƶ citizens about the scientific resources at ŷ���ڱ���Ƶ’s 24 federal labs and the impact of the labs’ research on the state.

Through this local concentration of scientists, the state is a global research leader in natural resource management, climate science and renewable energy, photonics, materials science and astrophysics.

The labs work closely with ŷ���ڱ���Ƶ’s research universities and technology companies. The governor’s awards and dinner is the major CO-LרS event to showcase the labs and raise funds to support the work of CO-LרS.