Optically Pumped Cesium-Beam Frequency Standard for GPS-III

Abstract : We describe an optically pumped cesium-beam frequency standard under development for deployment on the GPS-III satellite constellation. The objective of the project is to demonstrate the feasibility of a space qualified optically pumped cesium-beam frequency standard exhibiting a short-term stability of sigma y (Tau) <6 x 10(exp-12) tau (exp -1/2) with lifetime and reliability comparable to that of the current GPS-IIF cesium standards. In this paper, we report on the architecture and development progress of a prototype instrument that meets these goals with a minimal introduction of unproven technology. in particular, we discuss the design choices that have been made with particular emphasis on optical pumping and interrogation techniques, laser and optical technologies, and the realization of the prototype frequency standard. Preliminary performance data are presented.