Line-shape of dark line and maser emission profile in CPT

The paper is concerned with the line shapes of resonance phenomena observed in Coherent Population Trapping (CPT) applied to alkali atoms in a cell co ntaining a buffer gas. Significant asymmetries and departures from a Lorent zian shape have been observed in connection with the measurement of dark li nes and CPT maser emission profiles. Measurements are reported as a functio n of the power and frequency tuning of the laser used to create the CPT phe nomenon. The paper reports on different experimental conditions and a compa rison between theory and experiments is made for the cases of cesium and ru bidium in a buffer gas.