Abstract: In recent years, atomic devices for timing, field sensing and communication have been demonstrated in prototypes operating in field and space environments, but transfer into further miniaturized systems with higher stability, less complexity and the potential of scalable manufacturing remains a major technological challenge.

This talk will focus on our results in discrete hybrid integration of photonics, electro-optical components and atomic systems for operation in miniaturized devices. While combining high-precision spectroscopy of atomic vapor with microfabrication techniques opens up many exciting applications, we will focus on design, fabrication and performance of standalone plug-and-play atomic optical frequency references (AOFR). In space, these technologies enable new applications or bear the potential to improve existing ones. Clocks based on AOFR can improve the performance of time standards which are fundamental for everyday applications like communication and navigation with Global Navigation Satellite Systems.

We present results towards orbital deployment, highlight mission operation onboard sounding rockets using vapor-cell based AOFR and discuss developments to further improve stability using, e.g., two-photon spectroscopy of Rubidium vapor and Ramsey-Bordé interferometry of thermal Strontium. In the end, we will outline recent activities in field sensing and communication, which equally benefit from co-integration of photonic and atomic components, such as quantum memories and magnetometers