Rabi frequency measurement for microwave power standard using double resonance spectrum

In this paper we describe a basic experiment with the aim of developing a new type of microwave power standard that utilizes atomic resonances. The microwave field strength is determined from the oscillation of the population of atomic quantum states caused by the interaction between a microwave and Cs atoms (Rabi oscillation). A rectangular Cs glass cell was developed for this experiment and inserted in a WR90 waveguide. The observed frequencies of the Rabi oscillation were proportional to the microwave field strength, which demonstrated the feasibility of the new microwave power standard.