A primary critical hardware need that is common to all atomic quantum sensors including atomic clocks, inertial sensors, gravimeters, and electromagnetic sensors is laser and laser-frequency-stabilization subsystems for the specific manipulation of atoms and readout in the quantum sensor that is in a portable form factor and operational in real-world and harsh environments on sea, land, air, and space. Technical challenges remain to maintaining high frequency stability, frequency control, with lower SWaP form factors required for laser and frequency-stabilization subsystems while operating in real-world and harsh environments. In this effort Rydberg technologies will evaluate architectures for optimal atomic frequency-stabilization of a frequency-agile 510-nm coupler laser that uses electromagnetically induced transparency (EIT) signal from a modulated alkali gas cell to both (1) frequency-stabilize the coupler laser to <100 kHz (10 kHz goal) during signal reception operation and (2) provide frequency-agility with wavelength tuning over nanometers to access Rydberg levels and S-band and K-band RF transitions. In this effort to realize QRR-ready multi-color tunable Rydberg laser packages, we will exploit the fact that atom-based vapor-cell saturation and Rydberg-EIT spectroscopies offer stabilization approaches that provide mechanical and thermal robustness, as well as compactness. These are critical features that cannot be met with SOTA ultra-stable cavity references. The proposed atomic Rydberg-EIT laser lock seamlessly dovetails with the QRR sensors and hybrid electrode-integrated vapor-cell detectors because both types of cells are similar and use the same atomic transitions, ensuring laser frequency locks that are drift-free and free of laser-frequency-shifting schemes that are complex and/or not sufficiently agile. Anticipated
Benefits: The proposed work supports the advancement of JPLs Quantum Rydberg Radar (QRR) effort. QRR based on Rydberg atom sensing is poised to advance capabilities in remote sensing for Earth and space-based science missions in Surface Topography and Vegetation (STV). The work here will address needs in high-spatial and temporal resolution identified in the 2017-2027 Earth Science Decadal Survey. The stabilized laser subsystems developed in this effort will have impact on the many applications for Rydberg atomic sensing systems. The markets impacted include RF test and metrology, communication applications from long-wavelength to the growing 5G/6G markets, and millimeter and THz imaging applications.
