Laser Field Initiation of Higher Order Poles of S-Matrix-Optical Realization of Field Theoretic Models

We discuss the possibility of converting a simple pole in the radiative decay of a state into a pole of higher order by using resonant electromagnetic fields. This process of creation of higher order pole is controllable by the intensity of the laser field. We use density matrix and Liouville space and present the modification of the Lorentzian line shapes (Breit-Wigner formula) for example to ones involving square of Lorentzian and derivatives of Lorentzians.