Noise performance of a Rydberg atomic receiver

This paper systematically analyzes the key noise sources limiting the sensitivity of Rydberg atomic receivers. First, the quantum projection noise inherent to the system is modeled, as this noise sets the theoretical limit for receiver sensitivity. Second, the paper establishes the constraints relationship between photodetector noise and system sensitivity under both direct detection and heterodyne detection methods. Subsequently, this paper establishes the constraint relationships between the laser's intensity noise and receiver sensitivity, and between the phase noise and receiver sensitivity, respectively. The research reveals that the intensity noise of the probe light significantly exceeds that of the coupling light in its effect on receiver performance, while its phase noise exerts a comparable level of influence.