Study of the Rydberg atom cell sensitivity on the incoherent detection method

The Rydberg atom cell sensitivity on the incoherent detection microwave is analyzed as the probe laser noise is considered. First, the probe laser noise transfer characteristic is theoretically derived. Second, the minimum detectable microwave electric field intensity is obtained by simulation at different signal noise ratio of the input probe laser. These simulation results suggest that the microwave detection sensitivity of the Rydberg atom cell can be improved by two ways. One is to increase the input probe laser signal noise ratio. The other one is to decrease the Rabi frequency of the coupling laser. As the coupling Rabi frequency
$\Omega_{c}=2\times 10^{8}\left(rad/s\right)$
and the probe signal to noise ratio is 20.5dB, the minimum detectable microwave electric field intensity is
$1.976 (\mu V/\text{cm})$
.