Theoretical output probe gain G_p as a function of the two-photon detuning δ/γ and the geometrical phase match Δk_z with (a) a single pump field and (b) two pump fields. Here the excited state decay rate is γ = 2π × 5.75 MHz, the decoherence rate is γ_c = 0.5γ, the atom density is N = 4.5 × 10¹⁸ m⁻³, the length of the medium is L = 12.5 mm and the pump Rabi frequencies are Ω_P1 = 28γ and Ω_P2 = 30γ.