Fock states are interesting examples of non-classical states; They are fragile and lose their non-classicality in time scale. The preparation by projective measurement is random. The crucial part here is to consider: 1 Would it be possible to prepare them in a deterministic way by using a quantum feedback procedure? 2 Can these procedures protect them against quantum jumps? Single atom prepares Schrodinger cat state 1. Coherent field is prepared in C 2. Single atom is prepared in R1 in a super-position of state e and g 3. Atom shifts the field phase in two opposite directions as it pass through C: Super-position leads to entanglement in typical Schr�dinger cat Situation. 4. Atomic states mixed again in R2 maintains cat's ambiguity. 5. Detecting atom in e or g projects field into+or- cat state superposition. Phase Shift We choose a small Delta value to get a large phase-shift per photon. The non-linear terms in the expansion of the atom-field states make phase-shift per photon n-dependent Reconstructing Schr�dinger cat states by Max Ent Since the measured observables are close to parity, they are almost binary and the Max Ent method applies well. We have to perform the NG= 500 field displacements and measure the expectation values of the corresponding errors affected generalized parity operators with one Phase. Since the measurements do not change n, we use in each realization the information provided by 10 atoms which reduces the number of realizations necessary per displacement. The theoretical curves super-imposed to the experimental peak points are fits obtained with the values of these multipliers. The agreement between the experiments and the fits is quite good.