Low SWAP frequency combs for atomic clocks enabled by black phosphorus absorbers

Position, Navigation, and Timing (PNT) is critical in both commercial and defense sectors, affecting areas such as communications, navigation, reconnaissance, and electronic warfare (EW). PNT needs are typically met using the Global Positioning System (GPS). GPS signals, however, are vulnerable to disruption and system resiliency requires drastic improvement. While inertial measurement units (IMUs) can provide accuracy over brief periods, resilient PNT will require strategies beyond IMUs and large-format GPS satellites.Consequentially, the Air Force (AFRL) desires low SWAP-C frequency combs to enable portable atomic clocks, a critical technology for PNT. Current state-of-the-art atomic clocks are large, and vulnerable to environment noise. To overcome this, Iris Light and the University of Arizona propose to develop chip-scale photonic frequency combs. This will enable the transition from current cumbersome deployments to small craft leading to stable, ultraprecise, and redundant PNT at low SWAP-C.The STTR goal is to develop a new class of chip-scale frequency combs enabled by black phosphorus semiconductor ink acting as a saturable absorber.áIn Phase I, Iris Light and the University of Arizona (UA) will visit existing collaborators and new stakeholders across several AFRL efforts in photonic integration and chip-scale frequency combs to determine the most feasible solution pathway for initial deployment and transition. The team will define prototype specifications with Customers and End Users for test and evaluation in Phase II. The envisioned Phase II deliverables are prototype frequency comb chips at 1550 nm with gigahertz rates suitable for interacting with microwaves. These devices will serve as building blocks for photonic PNT systems for the Air Force and beyond.