About the Research Program

Solis1G: Development of Strontium-based optical lattice clocks for applications in space

Optical clocks based on ultracold atoms trapped in optical lattices offer some of the most precise means of accurate time measurements and have the potential to revolutionize modern timekeeping, which is why they are one of the prime candidates for a near-future redefinition of the SI second towards an optical transition to replace current frequency standards based on microwave transitions. Currently, such clocks are mostly confined to research laboratories, and while initial efforts in reducing unit footprints to make these clocks portable have been successful, there are many challenges to be addressed to truly bring optical lattice clocks into field application and to enable their future commercialization. One particularly interesting application is to use such clocks in space to enable a future navigational network based entirely on optical lattice clocks, to supplement and eventually replace the current global positioning system (GPS) to make use of the significant advantages of optical clocks.

The consortium of Solis1G addresses these challenges by developing a highly integrated, low-SWaP optical lattice clock based on ultracold Strontium-88 atoms and evaluating its use for future space application. The clock includes a full set of continuous-wave diode lasers at different wavelengths, necessary to address several optical transitions in Strontium for repumping, trapping, cooling and interrogation, all of which are locked to a single optical frequency comb. The comb serves as a broadband optical reference to achieve the narrow linewidths necessary to ensure optimal clock performance, and includes an autonomous control system for hands-off operation. In particular, Menlo Systems is developing a novel low-SWaP optical frequency comb and optical reference system for this project.

We gratefully acknowledge funding by the DLR/BMWK.