Abstract We have studied theoretically constructive interference via collision-aided radiative excitation in an open four-level system using a density matrix approach. The four-level system consists of a $\varLambda$-type three-level quantum-beat configuration driven by one laser field and a fourth level coupled by a vacuum mode. It is shown that through the incoherent process (collision), coherence between widely-separated doublets and subsequent constructive interference can be realized. We analyse the effects of the collision-induced coherent and incoherent decay rates, laser intensity, and energy separation of the doublets on the interference. Meanwhile, the constructive interference between the two transition pathways 3P1/2-4D and 3P3/2-4D via equal-frequency hybrid excitation and collision-aided radiative excitation in an Na2-Na system is experimentally observed. A good agreement between the theoretical and experimental results is obtained.
Received: 20 May 2001
Revised: 08 December 2001
Accepted manuscript online:
PACS:
42.50.Md
(Optical transient phenomena: quantum beats, photon echo, free-induction decay, dephasings and revivals, optical nutation, and self-induced transparency)
Fund: Project supported by the National Natural Science Foundation of China (Grant Nos 19734003 and 10074015).
Cite this article:
Yang Xi-Hua (杨希华), Sun Zhen-Rong (孙真荣), Ding Liang-En (丁良恩), Wang Zu-Geng (王祖赓) Constructive interference via collision-aided radiative excitation 2002 Chinese Physics 11 346
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.
