Power dependence of the shift caused by spurious spectral components in atomic fountain

In this paper we analyze the behavior of the frequency shift caused by a spurious spectral component in the microwave spectrum against variation of the excitation microwave field. The theory of the shift caused by the presence of spurs in the microwave spectrum was investigated in depth over many years, however for historical reasons the behavior was never analyzed when microwave power is varied far above optimum. The theoretical predictions are significantly different form the thermal beam case. Furthermore the pulsed operation of a Fountain, with generally a well defined cycle time, set some new constraints on the size of carrier sidebands even when they are symmetric.