Simplified five-level configuration. The Zeeman sublevels in ground state 6²S_1/2 F = 4 are represented by three states: |1⟩, |2⟩, and |3⟩, and state |4⟩ represents the other ground state 6²S_1/2 F = 3. A resonance pump light linearly polarized along the Z direction couples ground state 6² S_1/2 F = 4 and the excited state 6²P_1/2 F′ = 3 (represented by |e⟩) with Rabi frequency Ω_R. The total spontaneous decay rate of |e⟩ is Γ₀ = 2 π × 4.5 × 10⁶ Hz for cesium. The decay rates of |e⟩ to |1⟩ and |3⟩ are defined as η Γ₀, while the rate from |e⟩ to |4⟩ is θ Γ₀. The direction of the magnetic field is along the X direction.