The Defense Advanced Research Projects Agency (DARPA), notorious for its far-out and rather avant-garde research, has set itself the ambitious goal of identifying individual photons. If such a remarkable dream can be realized, its ramifications for all light-based technology will be truly revolutionary.
The new program, which will be further elaborated upon at an agency “information day” to be held in Arlington, VA on January 25, is called The Fundamental Limits of Photon Detection, and its aim is to assemble the preeminent minds from such disparate fields as quantum physics, engineering, and computer science to tackle a problem that has important military and civilian applications.
“The goal of the program is to determine how precisely we can spot individual photons and whether we can maximize key characteristics of photon detectors simultaneously in a single system,” explains Prem Kumar, a project head at DARPA, in a Factor article discussing the new project.
At the heart of the issue is the extraordinary difficulty inherent in detecting a single photon. That may seem counterintuitive, since technologies ranging from the simple to the sophisticated do it every day, to say nothing of our own eyes. But these record the passage of billions of photons; singling just one out of that vast noise requires a process of quantum mechanically modeling the trillions of atoms that even a single photon typically interacts with.
The computational power necessary for this kind of complicated modeling is simply staggering. Even the most powerful supercomputers currently online lack the requisite heft.
DARPA’s Fundamental Limits of Photon Detection program hopes to change this.
By spurring new advances, and taking advantage of recent developments in quantum information science and nano-fabrication technologies, scientists may soon nab their very first photon.
The implications of a technology that removes individual photon detection from the realm of crackpot theorizing, and into the world of practical, everyday reality, are truly astonishing, and touch upon virtually every field of human endeavor.
The roster of potentially affected fields reads like a litany of the hottest topics in modern science.
Imagine telescopes capable of isolating every unit of light from a star or a planet, enabling astronomers to reconstruct a planet’s appearance, its features, and even detect the telltale chemical signatures of life that would escape even the most powerful of conventional instruments. Imagine similar advances in microscopy, whether for pure research purposes, or for life-saving medical applications.
And this is to say nothing of how it would revolutionize photography, communications, even computer science itself.
Observes Kumar, “This is a fundamental research effort, but answers to these questions could radically change light detection as we know it and vastly improve the many tools and avenues of discovery that today rely on light detection.”