Quantum theory of two-photon micromaser and laser

In this thesis, we study the quantum theory of two-photon micromaser and laser. To begin with, we study the photon statistics of the two-photon micromaser by considering the interaction of a quantized single-mode field with an effective two-level atom through intermediate states. We present an exact solution for the for the photon distribution function and study the behavior is predicted. It is shown that, the gain contribution to the laser linewidth is equal to the two-photon gain parameter and is independent of the mean number of photons in the field. Finally, we study the the two-proton transitions in multi-level atomic system, proton statistics of three-level two-photon micromaser and two-photon transition in four-level atomic system by considering dye laser as an example. (orig./A.B.)