The two-level system in a strong light field

Nikolai B. Delone, В. П. Крайнов, V. A. Khodovoǐ

F. A. Hashmi, Shi-Yao Zhu

We investigate the influence of the additional third level on the dynamic evolution of a Two-Level system interacting with a coherent field in the strong coupling regime where Rotating Wave Approximation is not valid. We find that the additional level has great influence on the evolution of the system population. Our results show that the Two-Level model is not a good approximation in this strong light-matter coupling regime. We further investigate the parameter space where the Two-Level model can still be justified.

Ryosuke Hata, Nobuhiko Yokoshi, Hiroshi Ajiki +1 more

We theoretically propose a new method for generating up-converted coherent light from two-level systems (TLSs) coupled with a plasmonic nanocavity. The emission spectrum of a TLS excited by a strong laser exhibits a triplet structure called the Mollow triplet. If the lower Mollow sideband is tuned to the cavity mode energy, population inversion of a TLS occurs. When the driving laser is abruptly truncated under this condition, an up-converted photon is emitted from the TLSs. We also predict the up-converted superfluorescence from an ensemble of TLSs as a correlation effect among the excited states of the TLSs.

A. O. Melikyan, K. Kh. Simonyan

Tozaburo Otsu, Tadashi Watanabe

Galina A. Nemova