Rubidium Optical Space Clocks

Within the ROSC collaborative project, key technologies for optical frequency standards are developed on the basis of rubidium two-photon absorption for their future use in satellites. The performance of such standards is planned to exceed the stability and accuracy of current space-qualified clocks (GPS, Galileo). This requires consistent expansion of the activities funded thus far by the German Aerospace Center in the topic area of optical frequency standards (FOKUS, LASUS, KALEXUS, JOKARUS, OPUS). In ROSC, the examined portfolio for optical references will be extended with the addition of rubidium two-photon absorption, since this is where the proposers have identified the greatest potential for a considerable reduction of the Size Weight and Power (SWaP) budget with comparably high stability and accuracy. HU Berlin provides the project with scientific and technical support in all presented work packages, with an emphasis on the work to develop a 5S->5D two-photon standard as a key component of optical clocks in space, miniaturised gas cells and a setup for anodically bonded cells (work packages 2–4).