ATOMIC COHERENT POPULATION TRAPPING AND ITS APPLICATION IN A RAMAN-TYPE PHOTOIONIZATION SYSTEM WITH THREE BOUND STATES

We have studied the atomic coherent population trapping in a Raman-type, photoionization system with three bound states. The conditions for the system having two or one stable eigenstate are given. The influences of Fano asymmetric factors on the coberent population transfer are also analyzed.It is found that the property of the system having on]y one population trapping state consisting of the ground state, and one excited state, can be utilized to transfer the atomic initial population into one excited state.