A density matrix based analytical model is developed to study the coherent probe field propagation through a four-level V type system in presence of a coherent control field. The model allows coupling of the probe field from the upper ground level to both of the excited levels keeping the control field locked to a particular transition. The addition of an extra ground level to a conventional three-level V type system creates extra decay paths to the ground levels for the upper level population. A set of sixteen density matrix based equations are formed and then solved analytically under rotating wave approximation to study the probe response under steady state condition. The simulated probe absorption spectra shows absorption dip at the centre of a transparency window only under Doppler broadened condition although the conventional EIT window appears under Doppler free condition. The dependence of the field induced absorption signal on the Rabi frequency of the control field, population transfer rate among the ground levels and temperature of the vapour medium has been studied in details.
Magnetically Induced Transparency-Absorption and Normal-Anomalous Dispersion Characteristics of ${}^{87}\text{Rb}$ Medium or Any J-Type Configuration Atomic Vapors Subject to a Vector Magnetic Field and a Weak Resonant Pump
Alikhanyan National Laboratory (Yerevan Physics Institute)（阿利哈尼扬国家实验室（耶烈万物理研究所））；Institute for Physical Research, Armenian National Academy of Sciences（亚美尼亚国家科学院物理研究所）
Different Rise Times of Atomic Br M$_{4,5}$ 3d$_{3/2,5/2}$ Core Level Absorptions during Br$_{2}$ C $^{1}Π_{u}$ $1_{u}$ State Dissociation via Extreme Ultraviolet Transient Absorption Spectroscopy
University of California, Berkeley（加州大学伯克利分校）；University of Michigan Ann Arbor（密歇根大学安娜堡分校）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）
On the opportunity of spectroscopic determination of absolute atomic densities in non-equilibrium plasmas from measured relative intensities within resonance multiplets distorted by self-absorption
