Effect of Line Inhomogeneity on the Frequency of Passive Rb 87 Frequency Standards

Abstract

Frequency measurements versus microwave power (P,x), lamp temperature (TL), and cell temperature (T,) have been made on a passive Rb87 frequency standard. The lamp and integrated cell, upon which the measurements were made, are typical of the majority of the commercial rubidium standards in the field. This is the first report of the frequency dependence upon PVh. The data are discussed in terms of line inhomogeneity. A spatially varying resonant frequency of the atoms in the cell plus their relative immobility produces inhomogeneities of roughly the magnitude used in the analysis. The good qualitative fit of the calculations to our data makes us feel that this inhomogeneity is the cause of the observed dependence upon Pph and TL.