Kramers–Kronig relation in a Doppler-broadened Λ-type three-level system*
Wang Menga),b), Lu Xiao-Ganga), Bai Jin-Haia), Pei Li-Yac), Miao Xing-Xua), Gao Yan-Leia),b), Wu Ling-Ana), Fu Pan-Minga), Yang Shi-Pingb), Pang Zhao-Guangb), Wang Ru-Quana), Zuo Zhan-Chuna)
       
Experimentally measured (black dots) and theoretically calculated (red solid curves) absorption [(a)–(c)] and dispersion [(a′)–(c′)] curves of the probe beam as a function of Δ 1 for a coupling field intensity of 7 mW when Δ 2 = 0 MHz [(a) and (a′)], 300 MHz [(b) and (b′)], and 700 MHz [(c) and (c′)], respectively. Here, Γ 10 = 7.2 MHz, Γ 20 = 0.72 MHz, Γ = 5.75 MHz, γ = γ ′ = 0.12 MHz, and G 2 = 20 MHz. In panels (a)–(c), the maximum of the absorption is normalized to 1.