Abstract A theoretical research on the variation of the absorption and dispersion profiles and population distribution of each level in a ladder-four-level system driven by two coherent fields has been made. Whether the variation occurs or not depends on the effect of quantum interference, the detuning of the upper coherent field and the separation of the two intermediate levels. A dressed-state analysis is introduced to explain the numerical results.
Received: 07 August 2002
Revised: 30 November 2003
Accepted manuscript online:
PACS:
42.50.Gy
(Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption)
Li Yong-Fang (李永放), Sun Jian-Feng (孙建锋), Niu Yue-Ping (钮月萍) Variation of the absorption and dispersion profiles in a ladder-four-level system 2004 Chinese Physics 13 1251
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.
