https://doi.org/10.1140/epjd/s10053-025-01097-5
Regular Article - Optical Phenomena and Photonics
A study of phase sensitivity of transparency and absorption in a four-level N-type atomic system with microwave field
1
Department of Physics, University of Calcutta, 92 APC Road, 700009, Kolkata, India
2
Department of Physics, Seth Anandram Jaipuria College, 10-Raja Naba Krishna Street, 700005, Kolkata, India
3
Department of Physics, BITS Pilani, K.K. Birla Goa Campus, 403726, Goa, India
4
Department of Physics, Santipur College, 741404, Santipur, India
Received:
24
May
2025
Accepted:
13
November
2025
Published online:
24
December
2025
This paper presents a study of the phase sensitivity of the transparency and absorption when a microwave (MW) field connects the two ground energy levels of a four-level N-type configuration. This four-level N-type system can be considered with the hyperfine energy levels of the D1 and/or D2 lines of 87Rb atoms. The effect of the MW field on electromagnetically induced transparency (EIT) and on absorption (EIA) is investigated in a weak pump region. Furthermore, we demonstrate that a small absorption dip appears on the top of the EIT in the strong probe region and the absorption dip gradually increases with the increasing value of the MW field at a specific off-detuning position of the pump laser field. The optical Bloch equations for the four-level N-type system are derived and the equations are solved numerically to obtain the results under steady state condition. Additionally, we show that by adjusting the phase of the MW field, a narrow EIT or EIA feature is converted into Autler–Townes Splitting (ATS) under the strong pump conditions.
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© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
