Photonics project from DARPA seeks to break quantum-noise limit
NewsFebruary 07, 2025
ARLINGTON, Va. The U.S. Defense Advanced Research Projects Agency (DARPA) launched what it named the Intensity-Squeezed Photonic Integration for Revolutionary Detectors (INSPIRED) program that has as its goal to develop compact, cost-effective optical detectors that can operate at unprecedented sensitivities, enabling optical signals previously buried in quantum noise to be clearly detected.
DARPA gives some background information on the INSPIRED project: While optical detectors are essential for converting light into measurable signals -- enabling a range of critical technologies including fiber-optic communication, biological imaging, and motion sensors for navigation -- the sensitivity of these detectors is fundamentally limited by quantum noise, which prevents the detection of extremely faint signals in the most precision-demanding fields.
By harnessing “squeezed light,” -- a quantum state in which the certainty of either the amplitude or the phase of an electromagnetic wave is less certain as one of them is more certain -- DARPA aims to translate laboratory-based squeezed light techniques into deployable technology. The program, say DARPA officials, is leveraging advancements in chip-scale photonics to develop compact, integrated squeezed-light sources 40 times quieter than the quantum noise limit, a hurdle that will subsequently enable the creation of highly sensitive detectors that overcome traditional noise barriers, unlocking new possibilities in fields such as sensing, communication, and quantum computing.
“By taking squeezed light capabilities out of the lab, we aim to drive breakthroughs across defense, scientific, and commercial applications,” said Dr. Justin Cohen, program manager in DARPA’s Microsystems Technologies Office.
INSPIRED will be performed in two phases over three years: Phase 1 focuses on developing core squeezed-light components, with participation from eight research teams led by Hewlett Packard Enterprise, RTX BBN Technologies, Inc., Stanford University, University of Massachusetts at Amherst, University of California, Santa Barbara, University of Southern California, University of Virginia, and Yale University. DARPA kicked off the program by gathering the INSPIRED teams at the LIGO Hanford Observatory (Richland, Washington). “Commencing the INSPIRED program at the LIGO Observatory reflects our commitment to uncovering what’s possible when we push the limits of technology through collaboration and vision," Cohen stated.
The INSPIRED deliverable for Phase 2 is expected to be a complete squeezed-light detector, housed within a module the size of a deck of cards.
