Theory of line shape for nondegenerate optical transitions

Anatolii V. Mitin

Marina N. Popova

The inhomogeneous broadening of a zero-phonon line of an optical transition between nondegenerate and degenerate levels of a rare-earth impurity center in a crystal that is caused by random lattice deformations has been considered. Spectra of non-Kramers and Kramers rare-earth ions located at tetragonal and cubic sites have been investigated. Lines of a characteristic shape with a deep dip in the center have been detected.

Hermann Haken, Hans Christoph Wolf

Hermann Haken, Hans Christoph Wolf

Yehuda Nafcha, M. Rosenbluh, Pierre‐Luc Tremblay +1 more

We present experimental and theoretical investigations of the ground-state levels of the Cs cycling transition. We show that in such multilevel nondegenerate systems, the populations of the extreme Zeeman sublevels, under optical pumping, can have asymmetric (``dispersive'') line shapes as a function of laser frequency. A density-matrix model which takes into account optical, Zeeman, and hyperfine coherences, and allows for a fluctuating laser field, correctly predicts the experimental observations. A comparison of the density-matrix model with a rate-equation model demonstrates the role of coherences in the population distribution. Investigation of the effect theoretically and experimentally for \ensuremath{\sigma} and \ensuremath{\pi} laser polarizations is presented in the paper.

Hermann Haken, Hans Christoph Wolf