Program Summary
Atom-based devices have proven to be the most accurate means of measuring the physical world. Two areas of great promise are frequency metrology using optically probed trapped atom clocks and inertial sensing using optically cooled atom interferometry. Together, they could form the basis of a fully autonomous navigation and timing system, free from GPS. However, replicating these devices even at laboratory scale is still resource intensive, while integration of these laboratory-based quantum devices into a practical size, weight, and power has proven very challenging.
The largest contributor to this problem is the optical system; it must interface the collection of visible through near-infrared lasers and detectors to a gas of atoms contained in a vacuum cell. For optical atomic clocks and gyroscopes that use trapped atoms, this optical system comprises hundreds of individually aligned optics that form a photonic circuit. The Atomic-Photonic Integration (A-PhI) program seeks to reduce the barriers of integration and development by developing the equivalent optical system to these devices as a photonic integrated circuit (PIC). The target PIC will perform the functions of laser cooling, trapping, probing, and detection.
A-PhI aims to develop PICs for two device categories – clocks and gyroscopes. With each device category, there is at least one additional significant challenge. In the case of the atomic clock, the PIC(s) will require frequency micro-combs to enable optical frequency division for ultra-low phase noise microwave output. This would generate the world’s best microwave oscillator combination when considering the combinations of phase noise and volume. In the case of the atomic gyroscope, the challenge is matching or exceeding the un-trapped atom device performance in trapped-atom systems that are amenable to interfacing with PICs.
The program goal is to reduce the most significant technical challenges associated with miniaturizing and developing quantum devices to a fabrication problem capable of being implemented at scale in a foundry.