Phenomenological-operator approach to introduce damping effects on radiation field states

In this paper we propose an approach to deal with radiation field states wh ich incorporates damping effects at zero temperature. By using some well kn own results on dissipation of a cavity-field state, obtained by standard ab initio methods, it was possible to infer, through a phenomenological way, the explicit form for the evolution of the state vector for the whole syste m: the cavity field plus reservoir. This proposal turns out to be extremely convenient for accounting for the influence of the reservoir over the cavi ty field. To illustrate the universal applicability of our approach we cons ider the attenuation effects on cavity-field states engineering. The main c oncern of the present phenomenological approach consists in furnishing a st raightforward technique to estimate the fidelity resulting from processes i n cavity QED phenomena. A proposal to maximize the fidelity of the process is presented.