In an effort to improve sensors that rely on detecting light, DARPA has embarked on a photon hunt.
The agency's Fundamental Limits of Photon Detection, or Detect, project is focusing on better methods of detecting photons. "The goal of the Detect 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," said DARPA program manager Prem Kumar in an agency news release. "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."
Light detection is used in many applications, including lidar, photography and communications. "But even the most advanced detectors of photons—the massless, ghostlike packets of energy that are the fundamental units of light—are imperfect, limiting their effectiveness," DARPA said. "Scientists suspect that the performance of light-based applications could improve by orders of magnitude if they could get beyond conventional photon detector designs—perhaps even to the point of being able to identify each and every photon relevant to a given application."
"Current photon detectors, such as semiconductor detectors, superconductor detectors, and biological detectors have various strengths and weaknesses as measured against eight technical metrics, including what physicists refer to as timing jitter; dark count; maximum rate; bandwidth; efficiency; photon-number resolution; operating temperature; and array size," DARPA said. "There is currently no single detector that simultaneously excels at all eight characteristics. The fully quantum model developed and tested in Detect will help determine the potential for creating such a device."
This means developing quantum models of photon detection, but advances in quantum information sciences have made this easier. Detect will also tap into quantum measurement theory and experimentation, quantum information science and technology, semiconductor physics, superconductor physics, biological physics and quantum biology, quantum-limited amplification, device and system design and engineering.
