Neighboring transition effect-enhanced dressed four-wave mixing in rubidium hyperfine states

In this paper, we demonstrate that neighboring transition effects (NTEs) enhance the dressed four-wave mixing (FWM) in a ladder-type atomic system with hyperfine (hf) states. By comparing FWM signals in red- and blue- detuned regimes, we confirm that the enhancement and asymmetry of signals are governed by three key factors: NTE from collective contributions of EIT-mediated coherence and pure two-photon absorption (TPA) across multiple hf channels, transition probabilities of hf pathways and the neighboring-state openness modulating decay efficiency. Dressed-state analysis and theoretical calculations validate this mechanism. Furthermore, high-resolution spectra enable precision metrology of excited-state energy gaps (e.g., 17[Formula: see text]MHz resolution), advancing quantum light source design.