Figure 2

The noise of atomic superhet at different interaction lengths l. a). NPS of probe laser (\(P_{\text{np}}\)) and atomic superhet (\(P_{\text{na}}\)) at different interaction lengths l. b). Noise power of interaction noise (\(P_{\text{ni}}=P_{\text{na}}-P_{\text{np}}\)) as a function of \(N_{\text{a}}\) at different read-out frequencies f, where \(N_{\text{a}}=20\times \log{l}\) is the relative atom number relative to the number of atoms per unit interaction length (mm) in decibel. c). A and \(P_{0}\) (see main text) as a function of read-out frequency. The error bar of data points is the statistical results of five independent experiments