Interaction of an Atom (or More) with a Finite Number of Energy Levels with Light

Abstract

This thesis presents a treatment of two problems. The first is a treatment of the phase properties of a field mode interacting with a three-level atom. The second is a treatment of some aspects in the semiclassical two­ photon laser. We consider phase properties of the field interacting with a three-level atom with an additional Kerr medium for one-mode. This has been carried out using the new phase formalism of Pegg and Barnett. It is shown in particular that phase properties of the field reflect the collapse and revival phenomenon. The results for the phase probability, mean value andvari­ ance of the phase operator are obtained and compared with those based on earlier approaches. The effect of the Stark shift on the phase properties of the above­ mentioned model has been discussed. The investigation is extended further to the three-level atom in interaction with two modes with multi-photon processes. The influence of Stark shift when an ideal cavity is filled with a Kerr-like medium on the phase properties via non-degenerate Raman multi-photon processes has been discussed. The steady-state analysis of a single-mode two-photon laser is treated semi-classically by using the Maxwell-Bloch equations. We find similarities and significant differences between the one- and two-photon polarizations of the medium, population inversion and mode-pulling formulae. The spatia­ temporal dependence of the relevant magnitudes such as the field strength and the inversion are studied numerically. Also, the effect of an extra one­ photon field taking into account the two-photon pumping is discussed.