Interference effects in atomic coherent systems: spectral features

• Published in: Optics communications Vol. 217; no. 1; pp. 291 - 297
• Main Author: Sandhya, S.N.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2003; Elsevier Science
• Subjects: Effects of atomic coherence on propagation, absorption and amplification of light; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Optics; Physics; Quantum interference; Quantum optics; Resonance fluorescence; Strong-field excitation of optical transitions in quantum systems; multi-photon processes; dynamic stark shift; 42.50.Hz; Quantum optics; 32.80; Resonance fluorescence; Quantum interference; Theoretical study; Atomic coherence; Four level atom; Quantum interference phenomena
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/S0030-4018(03)01096-4

We study resonance fluorescence in a four-level ladder system and illustrate some novel features due to quantum interference and atomic coherence effects. We find that under three photon resonant conditions, in some region of the parameter space of the rabi frequencies Ω 1 , Ω 2 , Ω 3 , emission is dominantly by the level 4 at the line center even though there is an almost equal distribution of populations in all the levels. As one increases Ω 3 with Ω 1 and Ω 2 held fixed, the four-level system ‘dynamically collapses’ to a two-level system. The steady state populations and the the resonance fluorescence from all the levels provide adequate evidence to this effect.